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Franco MOGLIE

Pubblicazioni

Franco MOGLIE

 

178 pubblicazioni classificate nel seguente modo:

Nr. doc. Classificazioni
107 4 Contributo in Atti di Convegno (Proceeding)
64 1 Contributo su Rivista
7 2 Contributo in Volume
Anno Risorsa
2019 Multi-sensor platform for real time measurements of honey bee hive parameters
IOP Conference Series: Earth and Environmental Science
Autore/i: Cecchi, S.; Terenzi, A.; Orcioni, S.; Spinsante, S.; Mariani Primiani, V.; Moglie, F.; Ruschioni, S.; Mattei, C.; Riolo, P.; Isidoro, N.
Editore: Institute of Physics Publishing
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266895 Collegamento a IRIS

2019 Introduction to Scientific Computing Technologies for Global Analysis of Multidimensional Nonlinear Dynamical Systems
Nonlinear Structural Dynamics and Damping
Autore/i: Andonovski, Nemanja; Moglie, Franco; Lenci, Stefano
Editore: Springer International Publishing
Classificazione: 2 Contributo in Volume
Abstract: To determine global behaviour of a dynamical system, one must find invariant sets (attractors) and their respective basins of attraction. Since this cannot be made extensively with analytical methods, the numerical global analysis is currently the subject of intensive research, especially for strongly nonlinear, multidimensional dynamical systems. Numerical analysis in dimensions higher than four present a challenge, since it requires significant computing resources. Numerical methods used in global analysis that can benefit from high-power computing are those that can parallelize either data or task elaboration on a large scale. Mass parallelization comes with large number of difficulties, restrictions and programming hazards. When not implemented in compliance with hardware organization, data and instruction management can lead to severe loss of parallel algorithm performance. Systematic and methodical approach to design parallel programs is, therefore, critical to get the most from expensive high-power computing systems and to avoid unrealistic speed-up expectation. Considering these difficulties, the goal of this chapter is to introduce readers to the world of high-power computing systems for science and global analysis of strongly nonlinear, multidimensional dynamical systems. Topic covered are classification and performance of hardware and software, classes of computing problems and methodical design of programs. Two major hardware platforms used for scientific computing, clusters and systems with computational GPU are considered. Functionality of widely utilized software solutions (OpenMP, MPI, CUDA and OpenCL) for high-power computing systems is described. Performance of individual computer components are addressed so that the reader can understand advantages, disadvantages, efficiency and limits of each hardware platform. With this knowledge users can judge if their computation problem is suitable for mass parallelization. If this is the case, which hardware and software platforms to use. To avoid many traps of parallel programming, one of the methodical design approaches is covered. Topic is closed with example applications in science and global analysis.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264456 Collegamento a IRIS

2018 Effect of graphene oxide and metallic fibers on the electromagnetic shielding effect of engineered cementitious composites
JOURNAL OF BUILDING ENGINEERING
Autore/i: Mazzoli, A.; Corinaldesi, V.; Donnini, J.; Di Perna, C.; Micheli, D.; Vricella, A.; Pastore, R.; Bastianelli, L.; Moglie, F.; Mariani Primiani, V.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/255936 Collegamento a IRIS

2018 Over-the-Air Tests of High-Speed Moving LTE Users in a Reverberation Chamber
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
Autore/i: Micheli, Davide; Barazzetta, Massimo; Diamanti, Riccardo; Obino, Pietro; Lattanzi, Renzo; Bastianelli, Luca; Mariani Primiani, Valter; Moglie, Franco
Classificazione: 1 Contributo su Rivista
Abstract: High-speed trains are nowadays a reality in most countries. Internet services and connectivity are required by the passengers on board using smartphones and laptops. Nevertheless, the higher the speed, the bigger the issues that operators have to face to implement mobility and to reduce the effect of fast fading signal and Doppler shift, which may cause throughput reduction and problems to access the network. In the past, operators tried to optimize the cellular access to UMTS cells covering railways. Now that 4G networks have become mature and deployed, a similar approach needs to be optimized and implemented to LTE cells covering the same targets. We present the results of a testing campaign replicating real “high speed train” propagation scenarios, like a train running in open space or in tunnels with the help of a reverberation chamber. The chamber was partially filled by absorbing panels and equipped with rotating stirrers in order to approach the multipath propagation and to replicate the fading conditions that is typical of smartphones in a train coach. The effects of Doppler and its fast variations are presented, together with an analysis of the efficiency of different transmission solutions for tunnels (single input single output – SISO – cells propagating inside them). The testing sessions were performed under a collaboration program between Telecom Italia (in the paper referred as “operator”), Nokia Networks and Università Politecnica delle Marche. After the experiments in our laboratory, some features were introduced in the operator’s live network, covering the high-speed railway between the two Italian cities of Piacenza and Bologna.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/252568 Collegamento a IRIS

2018 On the Estimated Measurement Uncertainty of the Insertion Loss in a Reverberation Chamber Including Frequency Stirring
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Gifuni, Angelo; Bastianelli, Luca; Migliaccio, Maurizio; Moglie, Franco; Mariani Primiani, Valter; Gradoni, Gabriele
Classificazione: 1 Contributo su Rivista
Abstract: In this paper, we present an improved model of measurement standard uncertainty of the insertion loss in a reverberation chamber (RC), including frequency stirring. Differently from the previous model, the enhanced one does not require specific conditions on the parameter to be measured. Such an enhancement is applicable for all usable measurement conditions in RCs. Moreover, a majorant is derived, that is obtained under a weak condition on the coefficient of variation of the parameter to be measured. Results from measurements support the validity of both the proposed enhancement and the majorant.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266064 Collegamento a IRIS

2018 Shielding Effectiveness of Randomly Distributed Conductive Elements: Experimental Analysis and Simplified Model
IEEE International Symposium on Electromagnetic Compatibility
Autore/i: Bastianelli, Luca; Moglie, Franco; Mariani Primiani, Valter
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The shielding effectiveness of cementitious composites loaded by conductive fibers exhibits a particular frequency behavior that differs a lot from the case of powder fillers. The effects is ascribed to the random distribution of the conductive fibers inside the mortar that form a sort of grid with random side. Furthermore, contact among each fibers is not perfect and characterized by both a resistive and a capacitive nature. Some measurement data obtained by the nested reverberation chamber method are shown, and a simplified model is presented to predict such frequency behavior.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266063 Collegamento a IRIS

2018 Base-Case Model for Measurement Uncertainty in a Reverberation Chamber Including Frequency Stirring
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Gifuni, Angelo; Bastianelli, Luca; Moglie, Franco; Mariani Primiani, Valter; Gradoni, Gabriele
Classificazione: 1 Contributo su Rivista
Abstract: We address the uncertainty of reverberation chamber (RC) measurements in presence of both mechanical and frequency stirring (FS). A base-case model is derived for reverberation fields affected by the measurement uncertainty due to the lack of a perfect statistical uniformity of fields in a RC. It is found that the measurement uncertainty associated with the FS depends on both the total uncorrelated samples and the local insertion loss (IL). The local IL depends on the frequency stirring bandwidth (FSB). The model allows us for obtaining separate measurement uncertainty contributions. Measurements support the achieved uncertainty model. In particular, results show that the dependence on the IL is normally rather weak also when very wide FSBs are used.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251805 Collegamento a IRIS

2018 Experimental Analysis of the Aging Effects on Shielding Effectiveness of Cementitious Composites
2018 IEEE Symposium on Electromagnetic Compatibility, Signal Integrity and Power Integrity, EMC, SI and PI 2018
Autore/i: Bastianelli, Luca; Primiani, Valter Mariani; Moglie, Franco; Donnini, Jacopo; Mazzoli, Alida; Corinaldesi, Valeria; Gradoni, Gabriele; Micheli, Davide
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The shielding effectiveness of cementitious composites is analyzed by means of the nested reverberation chamber method. This feature is evaluated as function of time in order to estimate the aging effects. Different cementitious mixtures are considered and carbon/metallic fibers are put within the mortar in order to improve the shielding effectiveness considering the frequency band from 0.8 GHz up to 8.4 GHz
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266049 Collegamento a IRIS

2018 Applicability of Measurement Uncertainty Models in a Reverberation Chamber Including Frequency Stirring
2018 IEEE Symposium on Electromagnetic Compatibility, Signal Integrity and Power Integrity, EMC, SI and PI 2018
Autore/i: Gifuni, Angelo; Migliaccio, Maurizio; Bastianelli, Luca; Moglie, Franco; Primiani, Valter Mariani; Gradoni, Gabriele
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: We analyze the uncertainty of measurements carried out in a reverberation chamber. The adopted model includes the frequency stirring method and different K-Factor values. Two majorants are proposed to enhance the uncertainty computation of the chamber insertion loss.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266048 Collegamento a IRIS

2018 Correlation matrix methods to assess the stirring performance of electromagnetic reverberation chambers
WAVE MOTION
Autore/i: Gradoni, Gabriele; Moglie, Franco; Mariani Primiani, Valter
Classificazione: 1 Contributo su Rivista
Abstract: The use of correlation matrices to evaluate the number of uncorrelated stirrer positions of electromagnetic reverberation chambers has widespread applications in electromagnetic compatibility. We present a review of recent methods based on multivariate correlation functions that relates statistical inhomogeneities in space (frequency) to the reduction of uncorrelated cavity configurations. Full wave finite-difference time domain simulations of an actual reverberation chamber are performed through an in-house parallel code. The efficiency of this code allows for capturing extensive inhomogeneous/anisotropic reverberation fields at frequencies close to the lowest usable frequency (LUF) of the chamber. The concept of effective independent position is revised in light of random sampling and a model-driven relation with the probability distribution of correlation matrix entries is used to take into account spatial (frequency) inhomogeneities. Driven by extensive simulation data, an empirical probability density function is found for the correlation matrix elements to be non-central t-student distributed with asymmetry increasing towards low frequencies.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264933 Collegamento a IRIS

2017 ELECTROMAGNETIC PROPERTIES OF CARBON NANOTUBE REINFORCED CONCRETE COMPOSITES FOR FREQUENCY SELECTIVE SHIELDING STRUCTURES
CONSTRUCTION AND BUILDING MATERIALS
Autore/i: Micheli, D.; Vricella, A.; Pastore, R.; Delfini, A.; Buneno Morles, R.; Marchetti, M.; Santoni, F.; Bastianelli, L.; Moglie, F.; Mariani Primiani, V.; Corinaldesi, V.; Mazzoli, A.; Donnini, J.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240471 Collegamento a IRIS

2017 Testing of the Carrier Aggregation Mode for a Live LTE Base Station in Reverberation Chamber
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
Autore/i: Micheli, Davide; Barazzetta, Massimo; Carlini, Camillo; Diamanti, Riccardo; Mariani Primiani, Valter; Moglie, Franco
Classificazione: 1 Contributo su Rivista
Abstract: For the first time, the carrier aggregation feature of a live 4G-LTE base station (BS) is checked adopting a reverberation chamber as a propagating environment. To that purpose, two non adjacent bands were chosen: 800 and 1800 MHz and alternatively set as primary and secondary cells. The multipath conditions were tuned by adding the absorbing material inside the chamber and ranging from an empty condition with a rich multipath to a real environment like an indoor scenario. The latter is a very interesting and popular situation as it represents one in which people use mobile phones. The multipath variation effect on the BS performance was accurately verified by introducing power compensation in order to account for the variation of the chamber quality factor Q due to the insertion of absorbers. A complete over-the-air test was carried out by checking typical transmission quality parameters, that are of interest to manufacturers and mobile network operators. Results highlight differences between the performance of the two bands as a function of multipath degree and signal strength.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/236361 Collegamento a IRIS

2017 High performance FDTD simulations for chaotic electromagnetic environments
2017 IEEE MTT-S International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications, NEMO 2017
Autore/i: Moglie, Franco; Bastianelli, Luca; Gradoni, Gabriele; Mariani Primiani, Valter
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The performance of our FDTD code is analyzed in two HPC systems. A reverberation chamber is fully simulated and the statistical analysis reveals how the introduction of hemisphere scatters improves the chaotic nature of the random electromagnetic fields generated by the cavity, with particular emphasis on low frequencies.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251803 Collegamento a IRIS

2017 Reverberation chambers a la carte: An overview of the different mode-stirring techniques
IEEE ELECTROMAGNETIC COMPATIBILITY MAGAZINE
Autore/i: Serra, R.; Marvin, A. C.; Moglie, F.; Mariani Primiani, V. ; Cozza, A.; Arnaut, L. R.; Huang, Y.; Hatfield, M. O.; Klingler, M.; Leferink, F.
Classificazione: 1 Contributo su Rivista
Abstract: Reverberation chambers (RC), a name inspired in room acoustics, are also known in literature as reverberating, reverb, mode-stirred or mode-tuned chambers. In their basic form, they consist of a shielded metallic enclosure, forming a cavity resonator, together with some mode-stirring mechanism. The main goal of such stirring mechanism is to generate an amplitude-varying electromagnetic field that is ideally statistically uniform.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/248492 Collegamento a IRIS

2017 Stirring performance of helically distributed paddles
Proceedings of Electromagnetic Compatibility & Signal/Power Integrity (EMCSI)
Autore/i: Creta, Valerio; Bastianelli, Luca; Moglie, Franco; MARIANI PRIMIANI, Valter; Arnaut, LUK RAF
Editore: IEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The performance of a rotating stirrer made of helically positioned paddles is experimentally analyzed. The statistically independent positions are computed as a function of the number of paddles, paddle separation and relative tilt angle. With respect to a traditional single paddle wheel stirrer, the structure combines a helical path and just a simple engine required for the rotation. The analysis reveals an improvement in the lower frequency range where the chamber performance is more critical. The number of the paddles is limited by the distance and the tilt angle. The correlation between two adjacent paddles is also analyzed as function of the distance and the tilt angle. The activity suggests the need for optimization of all parameters.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251777 Collegamento a IRIS

2017 Full wave analysis of chaotic reverberation chambers
2017 32nd General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2017
Autore/i: Bastianelli, L.; Gradoni, G.; Moglie, F.; Primiani, V. Mariani
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this paper, we study possible ways to improve the Reverberation Chamber (RC) behavior. There could be benefits in deforming the RC rectangular geometry of the baseline cavity by inserting spherical diffractors into the RC or by titling the walls of the RC. We demonstrate that increased field disorder and randomization can be achieved with both the asymmetric structures in presence of the same mechanical stirrer. It is found that the improvement is prominent at low frequencies, with respect to the lowest usable frequency (LUF), which is consistent with results obtained by other investigators on similar RC structures. Numerical Finite-Difference Time-Domain (FDTD) simulations are performed to demonstrate the field chaoticity improvement in terms of both uncorrelated excitation frequencies and stirrer configurations.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266065 Collegamento a IRIS

2017 Reverberation chambers deformed by spherical diffractors
Proceedings of the 2017 International Symposium on Electromagnetic Compatibility - EMC EUROPE
Autore/i: Bastianelli, Luca; Moglie, Franco; Primiani, Valter Mariani; Gradoni, Gabriele
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Numerical FDTD full-wave simulations are performed in order to evaluate the behavior of a chaotic reverberation chamber. Performances are evaluated in terms of uncorrelated frequencies and antenna positions by using a correlation-based multivariate approach. The chaotic cavity geometry is obtained by including spherical diffractors inside the chamber. It is demonstrated that wall deformations enhance field uncorrelation and disorder within the investigated frequency range, including relatively low frequency of operation, thus assisting source stirring.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/252020 Collegamento a IRIS

2017 Reverberation chambers for testing LTE wireless communication systems
Proceedings of Electromagnetics in Advanced Applications (ICEAA)
Autore/i: Bastianelli, Luca; Gradoni, Gabriele; Micheli, D.; Barazzetta, M.; Diamanti, R.; Moglie, Franco; MARIANI PRIMIANI, Valter
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Reverberation chambers are successfully adopted to test last generation wireless communication systems. The aim is the replication of realistic propagation condition in outdoor and indoor situations where the multipath contribution statistically overlaps to the direct path between the base station and the user terminal. The insertion of quantified absorbing materials allows to tune the power delay profile, the Rician K-factor, and the coherence bandwidth according to real life situations.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251586 Collegamento a IRIS

2017 Helical Stirring for Enhanced Low-Frequency Performance of Reverberation Chambers
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Arnaut, Luk R.; Moglie, Franco; Bastianelli, Luca; Mariani Primiani, Valter
Classificazione: 1 Contributo su Rivista
Abstract: A novel class of volumetric mechanical mode stirring methods is introduced. One particular type, denoted as helical stirring, combines rotation and translation in a single motion. This technique is implemented, and its measured performance is compared to conventional circular stirring by the same paddle. It is observed that helical stirring can significantly increase the number of uncorrelated stir states at sufficiently low frequencies. Higher maximum- and lower minimum-to-average ratios of the magnitude and intensity of the received field are obtained that are traceable to a heavier tail of their probability density functions. While the helix pitch can be optimized per frequency, suboptimal values also yield considerable improvement. The use of a stir matrix facilitates the data analysis and estimation of ensemble statistics for arbitrary values of the helix pitch, beyond its experimentally realized discrete values.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/245096 Collegamento a IRIS

2017 A Comparison Between Different Reception Diversity Schemes of a 4G-LTE Base Station in Reverberation Chamber: A Deployment in a Live Cellular Network
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Barazzetta, Massimo; Micheli, Davide; Bastianelli, Luca; Diamanti, Riccardo; Totta, Matteo; Obino, Pietro; Lattanzi, Renzo; Moglie, Franco; MARIANI PRIMIANI, Valter
Classificazione: 1 Contributo su Rivista
Abstract: The uplink performance of a real fourth-generation long-term-evolution (LTE) frequency-division multiplexing base station was observed by adopting a reverberation chamber as propagating environment. In the downlink direction, the reception of the LTE signal is limited to mobile station receivers. On the other hand, different reception schemes could be implemented by the base station in the uplink direction. Interference rejection and coordinated multipoint reception criteria are based on spatial diversity and are analyzed in a rich multipath environment. These options could be susceptible to impairments due to the presence of Gaussian noise, also including the more realistic case of a discontinuous noise source. The testing session was carried out under a collaboration program between TIM S.p.A., Nokia, and Università Politecnica delle Marche, and it ended up by introducing envisioned reception solutions of the base station in a live customer’s cellular network.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/245679 Collegamento a IRIS

2016 Shielding effectiveness statistical evaluation of random concrete composites
2016 IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace) Proceedings
Autore/i: Bastianelli, Luca; Capra, Sofia; Gradoni, Gabriele; Micheli, Davide; Vricella, Antonio; Corinaldesi, Valeria; Mazzoli, Alida; Moglie, Franco; Mariani Primiani, Valter
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The shielding performance of random concrete composite samples are checked under a random excitation. It is achieved by means of a nested reverberation chamber system. Metallic fibers are randomly diffused in the concrete in order to improve shielding effectiveness from less than 10 dB up to an averaged value of 35 dB within a frequency range that includes communication system operating bands.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/236362 Collegamento a IRIS

2016 Optimization of 4G wireless access network features by using reverberation chambers: Application to high-speed train LTE users
European Microwave Week 2016: "Microwaves Everywhere", EuMW 2016 - Conference Proceedings; 46th European Microwave Conference, EuMC 2016
Autore/i: Barazzetta, Massimo; Micheli, Davide; Diamanti, Riccardo; Bastianelli, Luca; Moglie, Franco; Primiani, Valter Mariani
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A real 4G base station connected to live network of Telecom Italia and radiating into a reverberation chamber is used to investigate performances of fast moving terminals on board of high-speed trains. The results concern a testing campaign by replicating real high speed train propagation scenarios, like the train running in open space or in tunnels, with the aid of a reverberation chamber. This is partially filled by absorbing materials in order to approach the multipath propagation that is typical of a train coach, and equipped with two rotating paddels in order to replicate the signal fluctuations that are typical for the mentioned environments. The effects of Doppler shift and its fast variations are presented, together with an analysis of the efficiency of different transmission solutions for tunnels.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266066 Collegamento a IRIS

2016 Ballistic and electromagnetic shielding behaviour of multifunctional Kevlar fiber reinforced epoxy composites modified by carbon nanotubes
CARBON
Autore/i: Micheli, D; Vricella, A.; Pastore, R.; Delfini, A.; Giusti, A.; Albano, M.; Marchetti, M.; Moglie, F.; Mariani Primiani, V.
Classificazione: 1 Contributo su Rivista
Abstract: Overall goal of the research is to develop a material simultaneously able to absorb mechanical shocks and shield from electromagnetic interferences. Several layered composite materials aimed at such multi-functionality have been conceived and realized: the characterization has been carried out in terms of electromagnetic shielding effectiveness in the range 0.8–8.0 GHz and of energy absorbing capability upon impact of metallic bullets fired at about 400 m/s and 1000 m/s (such velocity allows to explore the low energy range of potential mechanical shocks in aerospace structures). The composite specimens under test are ∼3.5 mm thick tiles made of hybrid multi-scale material: the manufacturing has been performed by integrating several layers of Kevlar fabric and carbon fiber plies within a polymeric matrix reinforced by carbon nanotubes. The electromagnetic shielding effectiveness has been measured by means of a reverberation chamber; the performances of the layered composites approach the metallic behavior with values of shielding up to 80 dB. The impact tests have been carried out by using an in-house built linear electromagnetic accelerator, known as railgun; the results show that a thin and light tile of the designed composite material is able to absorb high energy impacts with local delamination of the layered structure.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/235951 Collegamento a IRIS

2016 Electrically Conductive DSP Cement Composites
JOURNAL OF APPLIED BIOMATERIALS & FUNCTIONAL MATERIALS
Autore/i: Mazzoli, Alida; Corinaldesi, valeria; Moglie, Franco; Mariani Primiani, Valter; Favoni, Orlando
Classificazione: 1 Contributo su Rivista
Abstract: Electromagnetic shielding and propagation in concrete structures are getting more and more interest in radiation hazard problems and wireless communications. The protection of sensitive environment is nowadays carried out by appropriate shielding room made of metallic walls. Even if effective they are heavy structures not adequate for the installation over existing building walls. The using of concrete composites filled by conductive elements represents a valid alternative to metallic shielded room since they can be adopted to directly build up the building walls and/or to easily plaster existing walls
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/236228 Collegamento a IRIS

2016 Parte II, Capitolo IV. Disinfestazione di Beni Culturali. Applicatori
Tecnologie innovative per il trattamento di beni culturali Applicazione delle onde elettromagnetiche per diagnosi e conservazione
Autore/i: Monti, Tamara; Moglie, Franco; Gradoni, Gabriele
Editore: Aracne
Luogo di pubblicazione: Ariccia (RM)
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/235949 Collegamento a IRIS

2016 Reliable Finite-Difference Time-Domain Simulations of Reverberation Chambers by Using Equivalent Volumetric Losses
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Moglie, Franco; Bastianelli, Luca; Mariani Primiani, Valter
Classificazione: 1 Contributo su Rivista
Abstract: Email Print Request Permissions A numerical code based on the finite-difference time-domain technique is adopted to simulate a large reverberation chamber including the stirrers and the actual antenna presence in the frequency range 200-1000 MHz. The power of the code lies in the parallelization that allows the execution on high-performance computers. Chamber losses are accounted for by introducing virtual volumetric losses in the hypothesis of ideal conductor walls. The correction that arises from this choice which allows us to speed up the numerical computation is verified by a comparison with the case of wall losses implemented by assuming a finite conductivity. The analysis of the statistics of the chamber field, stirrer uncorrelated positions, Rician K-factor, backscatter, and field uniformity returns overlapping results for the two techniques. The analysis of the spatial field correlation within a spatial grid shows a correlation greater than 0.5 in the whole frequency range and for all stirrer angles, so confirming the equivalence of the two methods to manage losses.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/235950 Collegamento a IRIS

2016 Effect of loss distribution on uncorrelated spatial points and frequency steps in reverberation chambers
IEEE International Symposium on Electromagnetic Compatibility
Autore/i: Bastianelli, Luca; Primiani, Valter Mariani; Moglie, Franco
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The inclusion of losses in FDTD codes allows a reliable simulation of actual reverberation chambers. The using of equivalent volumetric losses makes simulations faster than the adoption of equivalent wall losses. In particular, in the case of wall losses the effect of considering a variable wall surface impedance is also analyzed. These different ways to manage RC losses in simulations are compared by analyzing their effects on uncorrelated spatial points and frequency steps. The uncorrelation degree is checked by a multivariate approach based on Pearson's correlation matrix. Results highlight that the volumetric and wall loss methods return similar values for the investigated quantities, so that the more simpler volumetric approach can be successfully applied.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/258995 Collegamento a IRIS

2016 FDTD simulations of the losses in complex electromagnetic cavities
Bulletin of the American Physical Society
Autore/i: Moglie, F.; Bastianelli, L.; Mariani Primiani, V.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The simulations of complex electromagnetic cavities like reverberation chambers (RC) require a massive parallel computer to accurately account the complex three dimensional geometry. A parallel finite-difference time-domain (FDTD) code optimized for a massive parallel computer could lose its efficiency if the losses are concentrated in some part of the computation volume. For example, the simulation of the finite conductivity of the cavity metallic walls requires a significant overcharge for the computer processors that handle the boundary part of the global computational domain. Our in-house parallel FDTD code replaces the volumetric losses in every cell of the grid instead of the Ohmic losses on the walls. In this contribution, we evaluate the difference in the field distribution inside the cavity due to this replacement. Moreover, we compare the common RC statistics like the number of stirrer uncorrelated positions and the field uniformity, and the resources required for the two methods are reported and discussed. Finally, the numerical results will be compared with the measurements of the RC in our laboratory with a volume of 60 m^3 and plated steel walls in the frequency range 0.2-1.0 GHz, that includes the transition from the undermoded to the overmoded region.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251366 Collegamento a IRIS

2016 Evaluation of stirrer efficiency varying the volume of the reverberation chamber
2016 IEEE International Symposium on Electromagnetic Compatibility (EMC 2016) Proceedings
Autore/i: Bastianelli, Luca; Moglie, Franco; Mariani Primiani, Valter
Editore: IEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A full-wave finite-difference time-domain code is adopted to simulate a large reverberation chamber including stirrers, actual antennas, and losses. Maintaining the stirrer geometry unaltered, the chamber performance is analyzed by varying its volume. In particular, stirrer uncorrelated positions and field uniformity are analyzed for one and two stirrers. In the case of a chamber with only one stirrer, the number of uncorrelated positions depends on the chamber volume. It increases by reducing the volume. On the contrary, the field uniformity continues to gain benefits from a chamber enlargement. A chamber with two stirrers operating in a interleaved mode has already a very good performance which shows a weakly dependence on the volume variation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/236363 Collegamento a IRIS

2015 Power Boosting and Compensation During OTA Testing of a Real 4G LTE Base Station in Reverberation Chamber
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Micheli, Davide; Barazzetta, Massimo; Moglie, Franco; Mariani Primiani, Valter
Classificazione: 1 Contributo su Rivista
Abstract: A fully operational 4G long-term evolution (LTE) base station is tested in a reverberation chamber to analyze its performance in the presence of a multipath environment, typical of wireless and vehicular communications. Transmission quality parameters are measured ranging from the empty chamber situation (very rich multipath channel) to a very high loading condition to mitigate multipath. In that way, both outdoor and indoor propagation are accounted for a large attenuation is inserted between the transmitter and the antenna to reduce the signal received by the user to real-life values encountered in both outdoor and indoor environments. In these scenarios, operators may choose to transmit a constant power spectral density throughout all LTE spectrum, or to increase the energy of control channels at the expense of data channels in order to enforce transmission and provide better quality to the user, especially in poor radio conditions. This is called “power boosting,” and its effect is analyzed in this paper.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227716 Collegamento a IRIS

2015 Stirrer Efficiency as a Function of its Axis Orientation
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Bastianelli, Luca; Mariani Primiani, Valter; Moglie, Franco
Classificazione: 1 Contributo su Rivista
Abstract: The performance of a mechanical stirrer is numerically investigated, when its rotation axis is moved parallel to the three Cartesian axes in the reverberation chamber. We present results for the same stirrer, and for a stirrer with the same paddles but a different length to match the chamber sides. The number of uncorrelated stirrer positions is calculated using our finite-difference time-domain code, optimized for reverberation chamber simulations in high-performance computers. No significant differences were found in the simulation results when the stirrer axis and length are changed. However, a significant stirrer performance enhancement occurs when the blade width is increased.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/229295 Collegamento a IRIS

2015 Effect of the stirrer orientation and positioning on the reverberation chamber statistics
Cineca HPC Report 2015
Autore/i: Bastianelli, Luca; Mariani Primiani, Valter; Moglie, Franco; Gradoni, Gabriele
Editore: Cineca Consorzio Interuniversitario
Luogo di pubblicazione: Casalecchio di Reno (BO)
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/249540 Collegamento a IRIS

2015 Massive simulation of complex electromagnetic cavities
Bulletin of the American Physical Society
Autore/i: Moglie, F.; Bastianelli, L.; Mariani Primiani, V.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The analysis of the chaotic behavior of complex electromagnetic cavities takes benefit from the availability of a large amount of data on field samples. The application of a code running on a supercomputer is able to return a precise electromagnetic simulation of electrically large structures. The simulations of mode-stirred reverberation chamber (RC) were performed using an in-house parallel finite-difference time-domain (FDTD) code. The code is divided into three modules that are managed by a unique, single-step job: the electromagnetic solver based on the FDTD method; a fast Fourier transform (FFT) to obtain the frequency domain behavior; a statistical tool to obtain the RC properties. A unique run produces statistical results for all the investigated stirrer angles, without the burden of saving intermediate data. The code implements a hybrid parallelization as function of stirrer angle and cavity volume. Specifically, such a computation is known to be “embarrassingly parallel” with respect to the stirrer angle. The excitation is a Gaussian pulse modulated sinusoid at 1.1 GHz: the 95% bandwidth is 0.2 and 2 GHz. After the FDTD simulation is completed, the FFT module gives the frequency behavior of the fields in each point with a resolution of about 50 kHz.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251365 Collegamento a IRIS

2015 A mechanical mode-stirred reverberation chamber inspired by chaotic cavities
2015 IEEE Metrology for Aerospace (MetroAeroSpace)
Autore/i: Moglie, Franco; Gradoni, Gabriele; Bastianelli, Luca; Mariani Primiani, Valter
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A multivariate approach to the calculation of field-field correlation matrices is used to estimate the number of uncorrelated positions in a mode-stirred reverberation chamber (RC) inspired by chaotic cavities. The growth of the number of independent stirrer configurations is found to increase more rapidly with frequency than in a conventional RC. This is ascribed to the regular geometry forming the baseline cavity (screened room) of an RC, responsible for localizing energy and preserving regular (bouncing ball) modes. Smooth wall deformations are introduced in order to create underlying wave dynamical instability and then destroy survived regular modes. Numerical full-wave simulations are performed for a reverberation chamber with corner hemispheres and wall spherical caps. Field sampling is performed by moving a mechanical “carousel” stirrer. It is found that a wave-chaotic RC has improved performances in terms of lowest usable frequencies and number of uncorrelated cavity realizations of mechanical stirrers.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227745 Collegamento a IRIS

2015 Shielding effectiveness of carbon nanotube reinforced concrete composites by reverberation chamber measurements
Proceedings of the 2015 International Conference on Electromagnetics in Advanced Applications, ICEAA 2015
Autore/i: Micheli, D.; Marchetti, M.; Pastore, R.; Vricella, A.; Gradoni, G.; Moglie, F.; Mariani Primiani, V.
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The shielding effectiveness of carbon nanotube reinforced concrete composite is analyzed by using a reverberation chamber. The frequency band is 0.8-8 GHz and the weight percentages of carbon nanotube are 0, 1, 3 wt%. Results highlight that about 30 mm thick of 3 wt% reinforced concrete composite is able to perform a shielding effectiveness greater than 15 dB around 2 GHz and up to 30 dB at 8 GHz. The here reported results suggest the employment of carbon nano-powder reinforced concrete in building structures, having issues related to the electromagnetic interference mitigation, such as the influence on the medical devices working in hospital environments as well as the increasing of protection against electromagnetic attacks to strategic targets and sensible places.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/235037 Collegamento a IRIS

2015 Coupling Between Multipath Environments Through a Large Aperture
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
Autore/i: Gagliardi, Luigi; Micheli, Davide; Gradoni, Gabriele; Moglie, Franco; Mariani Primiani, Valter
Classificazione: 1 Contributo su Rivista
Abstract: A key issue in measuring the shielding of buildings against wireless communications signals is presented. We use a mode-stirred reverberation chamber (RC) to emulate the EM coupling through windows or doors. This is achieved experimentally by leaving the RC door open. The room hosting the RC is identified as an external semi-reverberant space, and thus used to generate the stochastic field exciting the internal RC through the door opening. Two methods for the transmission parameter measurement and shielding effectiveness estimation are compared: the first one consists in moving receiving antenna within a volume, the second one makes use of a rotating stirrer. The comparison confirms the interchangeability of the two techniques provided a proper averaging factor is introduced. This argument supports a quasi-ergodic hypothesis in imperfect and semi-open reverberating environments. The measured aperture SE is compared to a theoretical value given by an ideal reverberating environment.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227452 Collegamento a IRIS

2015 Effect of absorber number and positioning on the power delay profile of a reverberation chamber
2015 IEEE International Symposium on Electromagnetic Compatibility (EMC)
Autore/i: Bastianelli, Luca; Giacometti, Luca; Mariani Primiani, Valter; Moglie, Franco
Editore: iEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper shows how a reliable numerical code allows to optimize the number and the position of absorbers inside a reverberation chamber (RC) to properly reduce the chamber decay time. Simulation carried out on different situations demonstrate that the chessboard strategy is the best choice. Results are compared to measurements showing a good agreement. The RC power delay profile can be tuned close to that of real life environments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227866 Collegamento a IRIS

2015 Uncorrelated frequency steps in a reverberation chamber: A multivariate approach
2015 IEEE International Symposium on Electromagnetic Compatibility (EMC)
Autore/i: Gradoni, Gabriele; Bastianelli, Luca; Mariani Primiani, Valter; Moglie, Franco
Editore: IEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The use of correlation matrices to estimate the number of uncorrelated frequency steps of the reverberation chamber field is presented and discussed. Finite-difference time-domain simulations of an actual reverberation facility are performed through an in-house parallel code. The efficiency of this code allows for capturing the field behavior through large spatial volumes. Spatial field samples are used to construct the multivariate correlation function and to evaluate the number of uncorrelated frequencies over a broad band. Results are obtained for single rectangular component and total field. It is found that traditional (autocorrelation based) methods tend to overestimate the number of uncorrelated frequency steps, with respect to the proposed (multivariate) approach.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227867 Collegamento a IRIS

2015 Analysis of field probe perturbation in a mode stirred reverberation chamber
2015 IEEE International Symposium on Electromagnetic Compatibility & Signal Integrity
Autore/i: Bastianelli, Luca; Mariani Primiani, Valter; Moglie, Franco
Editore: IEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The residual stirring action of two commercially available electric field probes is experimentally and numerically analyzed. The capability to stir the reverberation chamber field is not negligible, and it alters the independent positions of mechanical rotating paddles when the spatial correlation matrix method is applied to evaluate them. The numerical code adopted for the simulations reveals its reliability and it can be employed to check probes during the design stage. Finally, we numerically evaluated the stirring effect of a conductor tripod that increases the independent positions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/226106 Collegamento a IRIS

2015 Advanced concrete materials for EMI reduction in protected environment and IEMI threats suppression
2015 IEEE 15th International Conference on Environment and Electrical Engineering (EEEIC)
Autore/i: Pastore, Roberto; Micheli, Davide; Vricella, Antonio; Morles, Ramon Bueno; Marchetti, Mario; Moglie, Franco; Mariani Primiani, Valter
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The enhancement of microwave shielding effectiveness of commercial concrete by the inclusion of carbon nanotubes powder is addressed and experimental testified. A microwave characterization is performed by direct measurements of materials dielectric parameters in the frequency range 1.7-2.6 GHz. A significant lowering of the microwave transmission magnitude is founded for the nanoreinforced material respect to the naked concrete. The results allow to evaluate the microwave shielding capability of wallshaped concrete structures: a shielding effectiveness grater than 50 dB is achieved for a 30 cm thick wall with carbon nanotube filling percentage of 3wt%. The route of nanoparticles filling within the composite mixture is straightforwardly included in the concrete typical on-site manufacturing procedures, thus planning out a time/cost saving procedure with the final aim to promote such typology of materials for commercial purpose in the next future. The here reported preliminary findings pave the way for the employment of carbon nano-powder reinforced concrete in building walls, in order to deal with issues related to the electromagnetic interference mitigation, such as the influence on the medical devices working in hospital environments as well as the increasing of protection against electromagnetic attacks to strategic targets and sensible places.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227769 Collegamento a IRIS

2014 Safety Investigation of a Magnetic Pulse Applicator for Heart Stimulation
IEEE TRANSACTIONS ON MAGNETICS
Autore/i: Alfredo De Leo; Valter Mariani Primiani; Paola Russo; Franco Moglie; Graziano Cerri
Classificazione: 1 Contributo su Rivista
Abstract: The safety area around the applicator of a high current pulse generator, able to magnetically stimulate the human heart, is characterized in terms of allowable induced current. The magnetic field produced by the adopted coil is computed using a complete analytical model to determine the limit area allowed for medical operators. The International Commission on Non-Ionizing Radiation Protection recommendation is adopted for the occupational exposure limits. The presence of a ferrite tile close to the stimulation coil is also investigated. The ferrite tile enhances the field level on the patient side, making the magnetic stimulation more efficient. Experimental validation demonstrates the model's reliability.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/177302 Collegamento a IRIS

2014 Effect of losses on the maximum-to-mean value in a mode-stirred reverberation chamber
2014 International Symposium on Electromagnetic Compatibility
Autore/i: Gabriele Gradoni; Valter Mariani Primiani; Franco Moglie
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Performances of reverberation chambers exhibit a non-trivial dependence on distributed losses. It is shown through numerical simulations that the average maximum-to-mean chamber field/power do not decrease with increasing losses as expected. Rather, it reaches an optimal value at moderate losses. Interestingly, the chamber field uniformity is also optimized at the same amount of losses. This behavior is accompanied by a progressive reduction of the quality factor and of the number of independent stirrer positions, indicating that losses augment the unstirred components as partial field coherence develops. A statistical model, the random coupling model, based on wave-chaos is used to shed light on the role of modal fluctuations and losses in the achievement of an optimal stress. It is found that the optimal condition is reached when losses extend the cavity bandwidth up to the average mode-to-mode spacing. Then, further increasing losses results in a suboptimal condition, for which the open-cavity behavior takes over, i.e., the ratio decreases.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/195305 Collegamento a IRIS

2014 Measurement and Simulation of Stirring Effects of Field Probes in a Reverberation Chamber
Atti della XX Riunione Nazionale di Elettromagnetismo
Autore/i: Luca Bastianelli; Valter Mariani Primiani; Franco Moglie
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The residual stirring action of two commercially available electric field probes is experimentally and numerically analyzed. The capability to stir the reverberation chamber field is not negligible, and it alters the independent positions of mechanical rotating paddles when the spatial correlation matrix method is applied to evaluate them. The numerical code adopted for the simulations reveals its reliability and it can be employed to check probes during the design stage.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/195302 Collegamento a IRIS

2014 Massive simulation and complete statistical analysis of reverberation chambers
Cineca HPC Report 2014
Autore/i: Luca Bastianelli; Luca Giacometti; Valter Mariani Primiani; Franco Moglie; Gabriele Gradoni
Editore: Cineca Consorzio Interuniversitario
Luogo di pubblicazione: Bologna
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212720 Collegamento a IRIS

2014 Numerical Simulations of Field Values, Wave Impedance, and Received Power Inside a Nonideal Reverberation Chamber
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Franco Moglie; Valter Mariani Primiani
Classificazione: 1 Contributo su Rivista
Abstract: The behavior of the ensemble averaged wave impedance computed by the rectangular field components and the impedance computed by the total field is numerically studied for a nonideal reverberation chamber. Evident departures from the medium intrinsic impedance are observed for the rectangular components when the ratio of the means and the mean of the ratios are exchanged. The power received by the antenna placed in the chamber is compared to that computed by the total field components, the rectangular field components using the wave impedance and the intrinsic impedance.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/144282 Collegamento a IRIS

2014 Broadband electromagnetic characterization of carbon foam to metal contact
CARBON
Autore/i: D. Micheli; R.B. Morles; M. Marchetti; F. Moglie; V. Mariani Primiani
Classificazione: 1 Contributo su Rivista
Abstract: We investigated how the electrical contact of carbon foam with metallic surface can reduce its shielding properties. The bubble structure of the foam does not ensure a good electrical contact with the metal, and it leads to a significant reduction of the shielding effectiveness. A finite element numerical simulation was carried out by adopting a bubble/pore model of the internal microstructure of the foam, recovered by means of scanning electron microscope images. Experimental tests were carried out by inserting carbon foam samples into a coaxial transmission line. Numerical results agree well with experimental result showing significant performance reduction with respect to an ideal electrical contact.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/139462 Collegamento a IRIS

2014 Reverberation Chamber Performance Varying the Position of the Stirrer Rotation Axis
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Mariani Primiani V.; Moglie F.
Classificazione: 1 Contributo su Rivista
Abstract: We analyzed how the position of the stirrer influences the reverberation chamber (RC) performance. We simulated a RC moving the rotation axis of the stirrer from a corner to the center. Simulation is carried out by a finite-difference time-domain code optimized for high-performance computers. Results show that the stirrer rotation center position weakly affects the most used statistical parameters.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/120862 Collegamento a IRIS

2014 A continued evaluation of the general method for determining the number of independent stirrer positions in reverberation chambers2014 International Symposium on Electromagnetic Compatibility
2014 International Symposium on Electromagnetic Compatibility
Autore/i: Stephan Pfennig; Hans Georg Krauthauser; Franco Moglie; Valter Mariani Primiani
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A method for estimating the number of independent stirrer positions in reverberation chambers is described in IEC 61000-4-21. This standard method is known to have disadvantages, but is a practical way to estimate the number of independent stirrer positions with comparatively low effort. A general method for determining the number of independent stirrer positions in reverberation chambers was presented in the previous papers. For this method the field distributions are measured for a given number of points within a defined test volume and as a function of stirrer positions. The field distributions of the used stirrer positions are tested for linear correlation using the Pearson correlation coefficient and a certain correlation threshold. In the following paper the evaluation of the general method is continued. Especially the dependency from the number of measurement points and the correlation threshold is investigated. The results are compared to the simulation results obtained by a numerical analysis of the given chamber.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/195303 Collegamento a IRIS

2014 Electromagnetic characterization and shielding effectiveness of concrete composite reinforced with carbon nanotubes in the mobile phones frequency band
MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY
Autore/i: D. Micheli; R. Pastore; A. Vricella; R.B. Morles; M. Marchetti; A. Delfini; F. Moglie; V. Mariani Primiani
Classificazione: 1 Contributo su Rivista
Abstract: The electromagnetic properties of carbon nanotube powder reinforced concretes are numerically and experimentally characterized. This typology of composite material is built by following the simple procedure usually adopted for the on-site concrete production. The dielectric parameters are investigated by means of waveguide measurements in the frequency band 0.75–1.12 GHz that is currently exploited in mobile phone radio access networks. The obtained results are used to compute the electromagnetic shielding effectiveness of large wall-shaped concrete structures. A shielding effectiveness up to 50 dB is obtained for a 15 cm thick wall when the carbon nanotube inclusion is raised up to 3 wt%.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/179131 Collegamento a IRIS

2014 4G-LTE base station output power estimation from statistical counters during over-the-air tests in reverberation chamber2014 International Symposium on Electromagnetic Compatibility
2014 International Symposium on Electromagnetic Compatibility
Autore/i: Massimo Barazzetta; Davide Micheli; Paolo Gianola; Franco Moglie; Valter Mariani Primiani
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The downlink transmission power of a 4G-LTE base station is quantified by means of statistical counters. They are build up analyzing the physical resource blocks allocated during transmission at different data throughputs. The analysis is performed during complete over the air tests carried out inside a reverberation chamber. The reverberation chamber allows to vary dynamic fading conditions by changing the stirrer rotating speed and the quality factor. Results are compared to direct antenna input power measurements obtained by a spectrum analyzer, in order to identify the better way to combine statistical counters. The analysis confirms the possibility to use this counters to monitor continuously the transmitted power over long time periods
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/195304 Collegamento a IRIS

2014 Over-the-air performance testing of a real 4G LTE base station in a reverberation chamber
2014 IEEE International Symposium on Electromagnetic Compatibility (EMC)
Autore/i: Massimo Barazzetta; Davide Micheli; Franco Moglie; Valter Mariani Primiani
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Fourth generation (4G) cellular systems have been nowadays rolled out already in several countries in the world. With networks open to commercial use, one of the key issues is how the quality perceived by the user is influenced by multipath propagation, like it may happen in indoor locations or in any kind of places where electromagnetic waves are partially reflected by walls and other objects. In order to verify this, the signal of a real 4G base station connected to the real radio access network of Telecom Italia has been transmitted into a reverberation chamber where a client was running FTPs using a 4G capable USB dongle as a modem. This paper describe the tests that have been performed and focus on how changes in propagation conditions affected the performances perceived by the user.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/197507 Collegamento a IRIS

2014 Dependence of reverberation chamber performance on distributed losses: A numerical study
2014 IEEE International Symposium on Electromagnetic Compatibility (EMC)
Autore/i: Gabriele Gradoni; Valter Mariani Primiani; Franco Moglie
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Finite-difference time-domain simulations of reverberation chambers exhibit a strong frequency dependence of field/power fluctuations on distributed losses. The performances of a reverberation chamber are calculated at different loss conditions and in a wide frequency band in terms of backscatter coefficient, and number of independent positions. Those performance indicators are related to field and power statistics through the scattering coefficients. A goodness-of-fit test is applied to analyze the statistical distribution functions of the numerical transmission scattering coefficient. Strong deviations from idealized distribution functions, some unexpected, are observed varying the chamber loading at both low- and high-frequencies. Observed phenomena are confirmed from the random coupling model, which reconciliates findings with the universal behavior of wave chaotic systems, as well as with previous studies of other investigators.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/197508 Collegamento a IRIS

2014 Railgun test of nano-reinforced layered composite materials for ballistic impact and electromagentic shielding
54th Israel Annual Conference on Aerospace Sciences 2014
Autore/i: Davide Micheli; Antonio Vricella; Roberto Pastore; Marta Albano; Mario Marchetti; Gabriele Gradoni; Franco Moglie; Valter Mariani Primiani
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A layered composite material have been manufactured and characterized in terms of electromagnetic shielding effectiveness and of energy absorbing capability upon impact of metallic bullets fired at about 400 m/s. This impact velocity is in the range of potential mechanical shock in aeronautical field. The composite material under test has a thickness of about 2mm. It has been manufactured by integrating several layers of Kevlar fabric and carbon fiber ply within a polymeric matrix reinforced by carbon nanotubes. The electromagnetic shielding effectiveness has been measured by using a reverberation chamber. Measurements approach the metallic behavior with values of shielding up to 80 dB. Impact test on material has been performed by using a linear electromagnetic accelerator typically known as railgun. Results show that a thin and light tile of nanoreinforced composite material is able to absorb one shot with a local delamination of the layered structure. Overall goal was to develop a material which is simultaneously able to absorb mechanical shock waves and protect electronic equipment from electromagnetic interference.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/181319 Collegamento a IRIS

2013 Performance and Immunity Evaluation of Complete WLAN Systems in a Large Reverberation Chamber
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: Renzo Recanatini; Franco Moglie; Valter Mariani Primiani
Classificazione: 1 Contributo su Rivista
Abstract: This paper concerns the use of a large reverberation chamber (RC) to test a wireless local area network system based on both 802.11b/g and 802.11n standards including multiple input and multiple output (MIMO). A whole link established between commercial devices operates inside the RC under different loading conditions, varying the stirrer rotating speed and the paddle dimensions. The effects of this multipath environment on system performance are checked measuring the number of cyclic redundancy check error and the number of data retries. The comparison between the two systems is done adopting the same chamber loading condition and also stressing the system reducing the load, up to the link connection limit. Results show the higher performance of the MIMO system, able to maintain a 6-Mb/s data rate connection also with a chamber quality factor of 21 000. The same RC is used to carry out a radiated immunity test. The undesired signal is both a modulated and continuous wave injected into the active channel and into adjacent channels. Results reveal the high robustness of the 802.11n standard with respect to b and g standards when it operates in a hostile environment reproduced by an RC
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/86573 Collegamento a IRIS

2013 Determination of the Reverberation Chamber Stirrer Uncorrelated Positions by Means of the Spatial and Frequency Correlation Matrix
Proceeding of 2013 International Symposium on Electromagnetic Compatibility (EMC EUROPE)
Autore/i: Gabriele Gradoni; Valter Mariani Primiani; Franco Moglie
Editore: IEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The uncorrelated stirrer positions of a reverberation chamber are computed by means of Pearson's correlation matrix. Two methods are adopted to populate the matrix, and results are compared with those given by standard method. The former uses the total electric field magnitudes sampled in a large spatial lattice in the working volume for each stirrer position. The latter uses the same quantity sampled within a frequency band for a single point in the working volume for each stirrer position. Results returned by the two methods are compared for a large chamber equipped by a rotating carousel stirrer.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/127668 Collegamento a IRIS

2013 Carousel Stirrer Efficiency Evaluation by a Volumetric Lattice-Based Correlation Matrix
Proceedings of 2013 IEEE International Symposium on Electromagnetic Compatibility (EMC)
Autore/i: Gabriele Gradoni; Valter Mariani Primiani; Franco Moglie
Editore: IEEE / Institute of Electrical and Electronics Engineers Incorporated:445 Hoes Lane:Piscataway, NJ 08854:(800)701-4333, (732)981-0060, EMAIL: subscription-service@ieee.org, INTERNET: http://www.ieee.org, Fax: (732)981-9667
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Recently, a new stirrer shape, the carousel stirrer, has been proposed to improve the reverberation chamber performances. In this contribution, we propose a method to compute the number of uncorrelated positions of the carousel stirrer. This method works by counting the low-correlation elements of a 3D lattice-based correlation matrix, each elements of the matrix being the Pearson correlation between two random vectors sampled at two different stirrer locations. We use adhoc FDTD code to simulate the Cartesian fields within the reverberation (lattice) region, for a large number of stirrer positions. Our analysis highlights dependence on the considered volume dimensions, the number of lattice field samples, and their spatial distance. The study also reveals the presence of periodic frequencies where uncorrelation dramatically reduces. A parametric analysis is presented to investigate the reason of this phenomenon which is evident only for two Cartesian field components.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/127670 Collegamento a IRIS

2013 Stochastic differential equation for wave diffusion in random media
Proceedings of 2013 International Conference on Electromagnetics in Advanced Applications (ICEAA)
Autore/i: Gabriele Gradoni; Roberto Pastore; Davide Micheli; Franco Moglie; Valter Mariani Primiani; Mario Marchetti
Editore: IEEE / Institute of Electrical and Electronics Engineers Incorporated:445 Hoes Lane:Piscataway, NJ 08854:(800)701-4333, (732)981-0060, EMAIL: subscription-service@ieee.org, INTERNET: http://www.ieee.org, Fax: (732)981-9667
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this work, we present a statistical analysis of the wave motion through random media with perfect spatial disorder of inclusions. It is assumed that such a disorder can be tackled with the random potential function theory, whence the propagation of waves naturally turns to a diffusion process. The associated Itoô drift-diffusion process, and its Fokker-Planck equation are derived. It is found that the “ensemble” wave, i.e., the collective wave motion, fluctuates in space as a geometric Brownian motion. Finally, the effect of a double-well potential with random (vibrating) valleys is studied qualitatively by the Monte Carlo method. In practice, this situation occurs for high concentration and perfect dispersion of conductive/dielectric fillers, i.e., whose location and orientation are completely randomized.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/127462 Collegamento a IRIS

2013 Stirrer Performance of Reverberation Chambers Evaluated by Time Domain Fidelity
Proceedings of 2013 IEEE International Symposium on Electromagnetic Compatibility (EMC)
Autore/i: Giuseppe Esposito; Gabriele Gradoni; Franco Moglie; Valter Mariani Primiani
Editore: IEEE / Institute of Electrical and Electronics Engineers Incorporated:445 Hoes Lane:Piscataway, NJ 08854:(800)701-4333, (732)981-0060, EMAIL: subscription-service@ieee.org, INTERNET: http://www.ieee.org, Fax: (732)981-9667
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The fidelity variation is considered inside a reverberation chamber. In particular, the scattering fidelity represents the decay law of the residual correlation between two cavity realizations. It is found that the fidelity is highly sensitive to stirrer geometry variations. Pertaining the chamber loading, the fidelity is also capable to reveal different location of absorbing materials. Results were also checked in terms of repeatability showing good reliability.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/127669 Collegamento a IRIS

2013 Determination of the electrical conductivity of carbon/carbon at high microwave frequencies
CARBON
Autore/i: Gabriele Gradoni; Davide Micheli; Valter Mariani Primiani; Franco Moglie; Mario Marchetti
Classificazione: 1 Contributo su Rivista
Abstract: We present an accurate measurement of the electrical conductivity of carbon/carbon (C/C) composites in higher range of microwave frequencies. The composite is an 8 mm thick C/C laminate 2D woven fabric, machined to create a rectangular waveguide. Transmission and reflection parameters are acquired within a broad frequency band, ranging from 23 to 30 GHz, and used for the evaluation of the power loss in the waveguide and to extract the C/C electrical conductivity. The obtained conductivity values at microwave frequencies are about ten times lower than those measured at very low frequencies. The effects of temperature are also investigated, and the variation of the conductivity with the temperature is reported.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/82793 Collegamento a IRIS

2013 Electromagnetic shielding of thermal protection system for hypersonic vehicles
ACTA ASTRONAUTICA
Autore/i: M. Albano; D. Micheli; G. Gradoni; R.B. Morles; M. Marchetti; F. Moglie; V. Mariani Primiani
Classificazione: 1 Contributo su Rivista
Abstract: The numerical simulation and the measurement of electromagnetic shielding at microwave frequencies of thermal protection system for hypersonic vehicles is presented using nested reverberation chamber. An example of a possible thermal protection system for a re-entry vehicle is presented. This system, based on carbon material is electromagnetically characterized. The characterization takes into account not only the materials but the final assembly configuration of the thermal protection system. The frequency range is 2–8 GHz. The results of measurements and simulations show that the microwave shielding effectiveness of carbon materials is above 60 dB for a single tile and that the tile inter-distance is able to downgrade the shielding effectiveness on the average to about 40 dB.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/86640 Collegamento a IRIS

2013 Quantifying volume changing perturbations in a wave chaotic system
NEW JOURNAL OF PHYSICS
Autore/i: Biniyam Tesfaye Taddese; Gabriele Gradoni; Franco Moglie; Thomas M Antonsen; Edward Ott; Steven M Anlage
Classificazione: 1 Contributo su Rivista
Abstract: A sensor was developed to quantitatively measure perturbations which change the volume of a wave chaotic cavity while leaving its shape intact. The sensors work in the time domain by using either scattering fidelity of the transmitted signals or time-reversal mirrors. The sensors were tested experimentally by inducing volume changing perturbations to a 1 m3 mixed chaotic and regular billiard system. Perturbations that caused a volume change that is as small as 54 parts in a million were quantitatively measured. These results were obtained by using electromagnetic waves with a wavelength of about 5 cm; therefore, the sensor is sensitive to extreme sub-wavelength changes of the boundaries of a cavity. The experimental results were compared with finite difference time-domain simulation results, and good agreement was found. Furthermore, the sensor was tested using a frequency-domain approach on a numerical model of the star graph, which is a representative wave chaotic system. These results open up interesting applications such as: monitoring the spatial uniformity of the temperature of a homogeneous cavity during heating up/cooling down procedures, verifying the uniform displacement of a fluid inside a wave chaotic cavity by another fluid, etc.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/86659 Collegamento a IRIS

2013 Reduction of satellite electromagnetic scattering by carbon nanostructured multilayers
ACTA ASTRONAUTICA
Autore/i: Davide Micheli; Roberto Pastore; Gabriele Gradoni; Valter Mariani Primiani; Franco Moglie; Mario Marchetti
Classificazione: 1 Contributo su Rivista
Abstract: We propose a low observable satellite covered by layered materials. The dielectric properties of the composite materials are analyzed using the coaxial air-line method. Our solution could result in cost-effective applications for satellite stealthness. The particle swarm optimization algorithm is used to design and optimize layered absorbers. The obtained reflection is below −20 dB in many frequency subranges, also under an oblique incident condition, within the band 2–18 GHz. The optimized layered absorbers are used as a cloack for cube satellites. In particular, we investigated a very simple geometry by using a finite element commercial software in the band from 2 to 18. Finally, the transmission through an aperture on the satellite surface is analyzed. It is highlighted that the optimized layered absorbers attenuate the electric field within the satellite, improving its immunity against electromagnetic interferences.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/89861 Collegamento a IRIS

2012 Reverberation chamber as a multivariate process: FDTD evaluation of correlation matrix and independent positions
ELECTROMAGNETIC WAVES
Autore/i: Gradoni, Gabriele; MARIANI PRIMIANI, Valter; Moglie, Franco
Classificazione: 1 Contributo su Rivista
Abstract: This paper evaluates the mode-stirring effciency in terms of uncorrelated positions of a mechanical stirrer operating inside a reverberation chamber (RC). The actual RC is simulated and viewed as a multivariate random process: the chamber field is sampled in a lattice of spatial points distributed uniformly over a volume of arbitrary dimensions. By adopting such a grid, the stirrer effciency is then computed through the correlation matrix, accounting for the residual correlation between stirrer positions. The second-order statistics are calculated averaging over the sampling volume. Results are presented for two stirrers that move in both synchronous and interleaved mode. A comparison with the traditional circular correlation (CC) method, for the determination of the uncorrelated positions, is done showing how CC overestimates stirrer effciency.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/81947 Collegamento a IRIS

2012 Quantifying Volume Changing Perturbations to a Wave Chaotic System
Bulletin of the American Physical Society
Autore/i: Taddese Biniyam; Gradoni Gabriele; Moglie Franco; AntonsenThomas; Ott Edward; Anlage Steven;
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Bulletin of the American Physical Society - APS March Meeting 2012 - Volume 57, Number 1. The Loschmidt Echo and Fidelity decay are used to measure perturbations on a quantum wave chaotic system. We extended these concepts to classical waves to detect perturbations. [1]. In this work, we show that volume changing perturbations to a classical wave chaotic cavity can be quantified with a sub-wavelength sensitivity. This is demonstrated both numerically and experimentally. A wave chaotic quasi-1D star graph model [2], was initially used to show the results. The quantification of electrical-volume changing perturbations to a one cubic meter aluminum box will be demonstrated experimentally; the experimental results are also supported by a finite difference time domain simulation of the box. Finally, the approach to quantify these perturbations will be shown to apply to a generic wave chaotic system by using a time domain version of our Random Coupling Model.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/72265 Collegamento a IRIS

2012 Numerical analysis of a new location for the working volume inside a reverberation chamber
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: F. Moglie; V. Mariani Primiani
Classificazione: 1 Contributo su Rivista
Abstract: This paper analyzes the performance of a reverberation chamber when the working volume (WV) is positioned inside the stirrer rotating volume. More precisely, considering a very large stirrer, its inner surface and axis are removed to gain a large space to be used as WV. The design of this new WV position and stirrer shape is done using our finite-difference time domain code, previously optimized for reverberation chamber simulations and tested with experimental results. The proposed setup increases the WV and improves the reverberation chamber behavior with respect to a traditional setup. Moreover, it needs just one motor to control the stirrer, and it does not require more complex mechanical part.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/65836 Collegamento a IRIS

2012 Electromagnetic shielding performance of carbon foams
CARBON
Autore/i: F. Moglie; D. Micheli; S. Laurenzi; M. Marchetti; V. Mariani Primiani
Classificazione: 1 Contributo su Rivista
Abstract: The electromagnetic shielding performance of carbon foams is measured using the nested reverberation chamber method in the frequency band 1-4 GHz, which is the frequency range of most cellular phones and microwave ovens. Good values of shielding effectiveness are obtained even with a small thickness of carbon foam. The results are used to assess the correct electrical conductivity values for the investigated materials using a multiple reflection model to compute the material transmission coefficient. The potential applications of such materials are in the lightweight microwave shielding structures that are partially transparent to optical frequencies.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/65394 Collegamento a IRIS

2012 Numerical and Experimental Analysis of the Performance of a Reduced Surface Stirrer for Reverberation Chambers
Proceedings of 2012 IEEE International Symposium on Electromagnetic Compatibility
Autore/i: Giacomo Bosco; Cesare Picciani; Valter Mariani Primiani; Franco Moglie
Editore: IEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents the numerical and experimental analysis carried out to check the performance of a way to reduce blade surface in mechanical stirring. In particular, the stirrer efficiency is quantified in terms of statistical independent positions, working volume field uniformity and Rician K-factor. The adopted numerical code reveals to be very reliable, compared to measurements, resulting in a powerful design tool.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/82801 Collegamento a IRIS

2012 Modeling and Measuring of Microwave Absorbing and Shielding Nanostructured Materials
Proceedings of EMC EUROPE 2012, International Symposium on Electromagnetic Compatibility
Autore/i: Davide Micheli; Roberto Pastore; Mario Marchetti; Gabriele Gradoni; Franco Moglie; Valter Mariani Primiani
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This work deals with the design of electromagnetic absorber of interest in radar absorbing material and microwave shielding systems. This absorber is based on a multilayer structure and the parameters taken into account are: number of layers, absorption maximization, microwave angle of incidence and frequency band. Design and optimization of the absorber are carried out using a winning particle optimization and are based on actual electrical parameters values. Such stochastic method leads to the best trade off between absorption properties and structure thickness, minimizing both the reflection coefficient and the global multilayer thickness. All simulations are confirmed by measurements.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/82800 Collegamento a IRIS

2012 Optimization of Multilayer Shields Made of Composite Nanostructured Materials
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: D. Micheli; C. Apollo; R. Pastore; D. Barbera; R. B. Morles; M. Marchetti; G. Gradoni; V. Mariani Primiani; F. Moglie
Classificazione: 1 Contributo su Rivista
Abstract: In this paper, we propose a multilayer nanostructured composite for broadband shielding applications. Layers disposal, electrical parameters, and thicknesses are optimized through a winning particle optimization algorithm to achieve the minimization of the transmitted waves. The structures are simulated by including the forward/backward scattering matrix formalism in the optimization code. The adopted algorithm is the recently introduced winning particle optimization. Manufacturing of the composites is grounded on the optimization procedure. Thanks to the macroscopic absorption features of such nanostructured layers, very thin and lightweight composites can be produced. Several weight percentages of multiwall carbon nanotubes are considered in composite base material manufacturing, also including 6wt% and 15wt% in order to enhance the electromagnetic shielding performance. Prototypes are tested in the microwave region, showing the reliability of the optimization procedure.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/65835 Collegamento a IRIS

2012 Numerical Simulation of Reverberation Chamber Parameters Affecting the Received Power Statistics
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: V. Mariani Primiani; F. Moglie
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents a reverberation chamber (RC) numerical modeling based on a discrete plane wave representation. In particular, the attention is focused on those parameters that may influence the field statistics. It is shown that a random choice of the angle of incidence, the initial phase, and the polarization in a particular range and a proper choice of the number of the plane waves allow us to reproduce the same behavior of experimental data. Both experimental and numerical field data are checked applying the Anderson--Darling (AD) test. More precisely, we count the frequencies where the received power statistics is rejected by the adopted goodness-of-fit test. This paper shows a correspondence between numerical and experimental parameters affecting the occurrence of the rejected frequencies, also giving a probability density function for the observed occurrence. The analysis is completed showing that the AD test rejection does not compromise the chamber use for typical radiated emission or radiated susceptibility tests.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/65834 Collegamento a IRIS

2012 ANALYSIS OF THE ENTROPY IN FAST TIME DOMAIN SIMULATIONS OF REVERBERATION CHAMBERS
Proceedings of the XIX RiNEm
Autore/i: Gradoni G; Mariani Primiani V; Moglie F
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this contribution, we investigate the entropy growth in a mode-stirred cavity simulated by the FDTD method. The adopted reverberation chamber is efficiently stirred by paddles and excited by a Gaussian pulse. It is observed that the entropy starts growing quadratically in time, then it increases linearly during the energy buildup, and it saturates after a few nanoseconds, when the onset of disordered fields occur. This allows for terminating the numerical simulations well before the Richardson time, as the asymptotic entropy is rapidly achieved. The analysis is based on the eigenvalues of the correlation matrix, calculated over a dense grid of spatial points, thus supporting the perspective of the reverberation chamber as a statistical multivariate process.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/80535 Collegamento a IRIS

2012 Electromagnetic Shielding of Oriented Carbon Fiber Composite Materials
2012 Proceedings ESA Workshop on Aerospace EMC
Autore/i: D. Micheli; S. Laurenzi; V. Mariani Primiani; F. Moglie; G. Gradoni; M. Marchetti
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper analyses the electromagnetic shielding measurements of carbon fiber composite structure. In particular the shielding effectiveness is measured applying the nested reverberation chamber method in the frequency range of 3.5 GHz - 8.5 GHz. This method ensure a realistic electromagnetic excitation of the sample under test characterized by a random polarization and incoming direction. The paper also describes the material manufacturing procedure and gives important details about the sample mounting technique. Three material samples are considered which differ in carbon fiber orientation and stratification. Obtained results highlight the capability of such materials to behave as high-performance shields in the microwave region.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/75590 Collegamento a IRIS

2012 Reverberation Chamber as a Statistical Relaxation Process: Entropy Analysis and Fast Time Domain Simulations
Proceedings of EMC EUROPE 2012, International Symposium on Electromagnetic Compatibility
Autore/i: Gabriele Gradoni; Valter Mariani Primiani; Franco Moglie
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this contribution, we investigate the entropy growth in a mode-stirred cavity simulated by the FDTD method. The adopted reverberation chamber is efficiently stirred by multiple paddles and excited by a Gaussian pulse. It is observed that the entropy starts growing quadratically in time, then it increases linearly during the energy buildup, and it saturates after a few nanoseconds, when the full onset of chaotic regime is developed. This allows for terminating the numerical simulations well before the Richardson time, as the asymptotic entropy is rapidly achieved. The analysis is based on the eigenvalues of the correlation matrix, calculated over a dense grid of spatial points, thus supporting the perspective of the reverberation chamber as a statistical multivariate process. The number of orthogonal eigenvectors (principal components) can be estimated and used as the number of statistically independent stirrer positions (degrees of freedom, cavity realizations). It is found that letting the chamber evolve for a very long time would gain only a few principal components, thus adding a negligible improvement in the stirring performances. Different mode-stirrer shapes can be investigated and their efficiency quantified by this method.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/82799 Collegamento a IRIS

2012 Absorbing cross section in reverberation chamber: experimental and numerical results
PROGRESS IN ELECTROMAGNETICS RESEARCH B
Autore/i: G. Gradoni; D. Micheli; F. Moglie; V. Mariani Primiani
Classificazione: 1 Contributo su Rivista
Abstract: Reverberation chamber (RC) test facility allows to determine the absorbing cross section (ACS) of lossy materials under a random field excitation. Measurements are based on the quality factor variation produced by the sample under test presence with respect to the empty chamber condition. Simulations are based on the representation of the RC electromagnetic field by means of a random plane wave superposition. A finite-difference time-domain code is used to compute the material absorbed power and to recover a numerical ACS. The method sensibility is stressed by application to small size samples. Comparison between numerical and experimental data reveals a satisfactory agreement. Results for different materials are presented in the paper: soft foam absorbers, carbon foam sheets, and carbon/carbon sheets.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/81804 Collegamento a IRIS

2012 Experimental and Numerical Analysis of a Carousel Stirrer for Reverberation Chambers
Proceedings of 2012 IEEE International Symposium on Electromagnetic Compatibility
Autore/i: Dario Fedeli; Matteo Iualè; Valter Mariani Primiani; Franco Moglie
Editore: IEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper analyzes the performance of a reverberation chamber equipped by a “carousel” stirring system. The working volume is positioned inside the stirrer rotating volume. More precisely, the carousel consists of several vertical strips that rotate around a central axis and having a total diameter as large as possible compared to chamber dimensions. An FDTD code, optimized for reverberation chamber simulations and tested with experimental results, is used to analyze the chamber performance as function of strip number and width. The proposed setup increases the working volume and improves the reverberation chamber behavior with respect to a traditional setup. Moreover, it needs just one motor to control the stirrer, and it does not require more complex mechanical part. All simulations are compared to measurements showing a good agreement.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/82802 Collegamento a IRIS

2011 A realistic model for the analysis of heart magnetic stimulation
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
Autore/i: A. P. Pastore; A. De Leo; R. De Leo; G. Della Chiara; V. Mariani Primiani; F. Moglie; G. Cerri
Classificazione: 1 Contributo su Rivista
Abstract: The aim of the paper is the development of an accurate numerical model to compute the current density flowing through the heart of a virtual human body, and induced by an external electric or magnetic excitation. The model has been experimentally validated and then applied to investigate the main characteristics of the heart magnetic stimulation. This has been carried out by comparing the current density induced in the cardiac region by an external magnetic pulse with the corresponding quantity due to the more traditional electric source. Magnetic stimulation is studied because it offers some advantages: in fact, compared with the electrical stimulation, this technique is contactless and might allow the stimulation of a dressed patient. The design constraint of the whole system is represented by the current density, whose waveform and intensity are a compromise between the strength of the magnetic induction field and the pulse rise time.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/54452 Collegamento a IRIS

2011 Analysis of the Independent Positions of Reverberation Chamber Stirrers as a Function of Their Operating Conditions
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: F. Moglie; V. Mariani Primiani
Classificazione: 1 Contributo su Rivista
Abstract: The independent positions of the stirrers are computed when one or two stirrers rotate inside the chamber. In the case of the two operating stirrers, they are moved in both tuned and stirring modes. In the tuned mode, they are rotated in a synchronized or interleaved way, showing that this second modality yields a larger independent position number. In the stirring mode, both modalities are replicated varying the rotation speed. In the case of one stirrer and two synchronized stirrers, the independent positions are computed using the classical autocorrelation function, whereas in the case of two completely independent stirrers a 2-D autocorrelation is proposed. The result obtained in this second way does not depend on the order chosen to move the stirrers. The performance of the stirrers is also verified checking the ratio between the maximum and the average received power inside the chamber, the statistics of the received power by applying a goodness-of-fit test, and the uniformity of the field in some points of the working volume. Tuned and stirring operating modalities are also compared in terms of measurement time, calibration and software complexity, motor stress, and so on.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/55330 Collegamento a IRIS

2011 Broadband Electromagnetic Absorbers using Carbon Nanostructure-Based Composites
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
Autore/i: D. Micheli; R. Pastore; C. Apollo; M. Marchetti; G. Gradoni; V. Mariani Primiani; F. Moglie
Classificazione: 1 Contributo su Rivista
Abstract: In this paper, we present the design of nanostructured multilayer absorbers, carried out with the aid of a genetic algorithm (GA). Waveguide measurements are performed to recover the dielectric properties of micrographite single-walled carbon nanotube, micrographite walled carbon nanotube, carbon nanofiber, and fullerene-based composite materials. Conductive fillers are uniformly dispersed in an epoxy resin at different weight percentages (1, 3, 5 wt.\%). The electromagnetic (EM) analysis is performed embedding the forward/backward propagation matrix formalism in an in-house GA, thus able to carry out optimization upon oblique incidence over a finite angular range. Developed code minimizes both the reflection and the transmission coefficients under the thickness minimization constraint. Comparison between micrographite and nanopowders absorbers is presented and discussed, when a broadband quasi-perfect absorber is achieved among the $X$-band combining the two filler families, i.e., exhibiting a loss factor greater than 90\% in most of the band, for a thickness of about 1 cm. It is demonstrated that the nanofillers with higher aspect ratio mainly contribute to the EM absorption. Findings are of interest in both radar-absorbing material and shielding structures.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62796 Collegamento a IRIS

2011 Determination of reverberation chamber field uniformity and independent positions: full 3D FDTD simulations using high performances computers
ISCRA 2011
Autore/i: F. Moglie; V. Mariani Primiani
Editore: CINECA
Luogo di pubblicazione: Casalecchio di Reno, Bologna, Italy
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/96062 Collegamento a IRIS

2011 Numerical Determination of Reverberation Chamber Field Uniformity by a 3-D Simulation
Proc. of the 10th Int. Symposium on Electromagnetic Compatibility (EMC Europe 2011)
Autore/i: MARIANI PRIMIANI, Valter; Moglie, Franco
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents a 3-D reverberation chamber simulation. An optimized FDTD numerical code runs accounting for the presence of two stirrers in the chamber. A real log-periodic antenna is modeled as field source. Stirrer rotations are also included by a proper parallelization of the code. The chamber electric field is computed within a defined working volume when one, two or three stirrers rotate. In the case of multiple stirrers both synchronized and interleaved moving modality are analyzed. Field uniformity is computed in the working volume according the IEC standard procedure.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/63566 Collegamento a IRIS

2011 Modeling of the human exposure inside a random plane wave field
PROGRESS IN ELECTROMAGNETICS RESEARCH B
Autore/i: F. Moglie; V. Mariani Primiani; A. P. Pastore
Classificazione: 1 Contributo su Rivista
Abstract: The specific absorption rate (SAR) of a human body exposed to a random field inside a reverberation chamber (RC) has been modeled. The exciting field is simulated using the plane wave integral representation which is numerically solved by a superposition of N plane waves randomly generated and repeated M times to reproduce the same statistics of an RC. An experimental validation, carried out by means of known saline solutions, confirms the reliability of this method. The obtained results at various frequencies for the adopted “Visible Human Body†and for some tissues well highlight the absorption percentage. The frequency behavior of the total SAR reveals the resonance of the human body around 75 MHz, in spite of the chaotic source.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/54909 Collegamento a IRIS

2011 An innovative numerical model for the microwaves heating
4th International Conference on Electromagnetic Fields, Health and Environment - EHE2011
Autore/i: Pastore A.P.; Moglie F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: An object heated in a microwaves oven, can be analyzed as the same object irradiated and heated by a superposition of plane waves. In particular it is possible to calculate the absorbed power distribution on the object, with the numeric technique Finite Differences – Time Domain (FDTD).
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/55943 Collegamento a IRIS

2011 System Throughput and Immunity Analysis of a 802.11n WLAN in a Large Reverberation Chamber
2011 IEEE International Symposium on Electromagnetic Compatibility
Autore/i: V. Mariani Primiani; F. Moglie; R. Recanatini
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents some results concerning the use of a reverberation chamber (RC) to test a wireless local area network (WLAN) system based on 802.11n standard. The whole link (root and non-root bridge) operates inside the RC under different chamber loading conditions and varying the stirrer rotating speed. The effects of this multipath environment on system performances are checked measuring three transmission quality estimators: the ping average round trip time, the number of cyclic redundancy check (CRC) error, and the number of data retries. The behavior of these parameters is also analyzed changing the modulation and coding scheme (MCS) index using both one spatial stream and two spatial streams (MIMO). The same RC is used to carry out a radiated immunity test. The undesired signal is both a modulated and continuous wave injected into the active channel and into adjacent channels. The modulated wave is that prescribed by the IEC 61000-4-3 standard. Results reveal the high robustness of the 802.11n standard with respect to b and g standards when it operates in a hostile environment reproduced by an RC.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62560 Collegamento a IRIS

2011 Reverberation Chambers: Full 3D FDTD Simulations and Measurements of Independent Positions of the Stirrers
2011 IEEE International Symposium on Electromagnetic Compatibility
Autore/i: F. Moglie; V. Mariani Primiani
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper describes the developing and the testing of our FDTD code to simulate the whole reverberation chamber. In order to reduce computer load some approximations were introduced, and we validated the results with the experimental ones measured in our reverberation chamber. Simulated and measured results were compared using the same statistical software. In addition, the computations easily provide other results that cannot be obtained by measurements like the ones that regard field distribution inside the cavity. The developed FDTD code is able to simulate the statistical properties of an RC as function of its dimensions and stirrer geometry. Many numerical techniques haves been proposed to simulate reverberation chambers. Every method requires very large computer resources if a full 3D simulation is done. The developed FDTD code is able to simulate different geometries and movements of the stirrer(s) allowing the designer to obtain the best configuration using the simulator, and saving time for experimental tests. Simulations integrate experimental measurements when long measurement time or destructive tests are required.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62559 Collegamento a IRIS

2010 On the use of a reverberation chamber to test the performance and the immunity of a WLAN system
Proceedings of 2010 IEEE International Symposium on Electromagnetic Compatibility
Autore/i: MARIANI PRIMIANI, Valter; Moglie, Franco; Recanatini, Renzo
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents some results concerning the use of a reverberation chamber (RC) to test a wireless local area network (WLAN) system using the standard IEEE 802.11b/g. The whole link (access point and terminal) was operating inside the RC under different chamber loading conditions and varying the stirrer rotating speed. The effects of this multipath environment on system performances were checked measuring three transmission quality estimators: the ping average round trip time, the cyclic redundancy check (CRC) error, and the data retries. The behavior of these parameters, as function of the bitrate set for the link, was also analyzed. The same RC was used to carry out a radiated immunity test on the same WLAN. The undesired signal was both a modulated and continuous wave injected into the used channel and into adjacent channels. The modulated wave is that prescribed by the IEC 61000-4-3 standard.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/46056 Collegamento a IRIS

2010 Numerical simulation of LOS and NLOS conditions for an antenna inside a reverberation chamber
JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS
Autore/i: MARIANI PRIMIANI V; F. MOGLIE
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents a numerical analysis of the voltage received by an antenna operating in a complex environment such as a reverberation chamber (RC). Both scattered and direct components were considered for the excitation of the receiving antenna, ranging from line-of-sight (LOS) to non-line-of-sight (NLOS) conditions. A numerical solution based on a finite difference time domain code was achieved and compared with measurements inside a reverberation chamber. The method allows to balance the amount of random contributions, direct contribution and deterministic multipath contributions just like in actual propagation conditions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/51082 Collegamento a IRIS

2010 A Numerical Model for the Analysis of Heart Magnetic Stimulation
Proceedings of the XVIII RiNEm
Autore/i: G. Cerri; A. De Leo; R. De Leo; G. Della Chiara; V. Mariani Primiani; F. Moglie; A. P. Pastore
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: An accurate numerical model has been developed to evaluate the current density flowing through the heart of a virtual human body to compare an electric and a magnetic excitation. This model is useful to investigate cardiac stimulation with a magnetic pulse. The waveform and intensity of the current density are a compromise between the strength of the magnetic induction field and the pulse rise time.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/68215 Collegamento a IRIS

2010 Numerical and Experimental Analysis of Anomalous Statistics Situations in Reverberation Chambers
Proceedings of the XVIII RiNEm
Autore/i: V. Mariani Primiani; F. Moglie
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper analyzes the occurrence of frequencies with anomalous stirring in a reverberation chamber. Both experimental and numerical field data are checked applying the Anderson-Darling test. The presence of these frequencies is unavoidable, even eliminating evident causes, such as antenna bias. In particular, the parameters that influence this occurrence, such as small perturbations of the relative position of the antenna and chamber quality factor, are analyzed. In the case of simulated field, based on plane wave expansion, occurrences are still present and their variations are related to the change in the field observation points, change in the plane wave set randomly generated, and change in the number of plane waves used to represent the field. The paper shows a correspondence between numerical and experimental parameters affecting the occurrence f the anomalous stirring frequencies.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/68216 Collegamento a IRIS

2010 Safety aspects of a system for heart stimulation induced by a magnetic pulse
Proceedings of EMC Europe 2010
Autore/i: CERRI GRAZIANO; DE LEO ALFREDO; DE LEO ROBERTO; DELLA CHIARA GIUSEPPE; MARIANI PRIMIANI VALTER; F. MOGLIE; PASTORE ANNA PIA; RUSSO PAOLA
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A system for heart stimulation induced by a magnetic pulse has been designed. It is characterized by high intensity current pulses, and therefore safety may arise for operators and medical devices during its use. In particular, in this contribution safety considerations are analyzed and shielding actions are proposed in order to make cardiac stimulation available in hospital environment.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/46261 Collegamento a IRIS

2010 Numerical Modeling of the Reverberation Chamber Method for the Measurement of Material Absorbing Cross Section
Proceedings of EMC Europe 2010
Autore/i: GRADONI GABRIELE; F. MOGLIE; MARIANI PRIMIANI VALTER
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Reverberation chamber (RC) test facility allows to determine the absorbing cross section (ACS) of lossy materials under a random field excitation. Measurements are based on the quality factor variation produced by the sample under test presence with respect to the empty chamber condition. Simulations are based on the representation of the RC electromagnetic field by means of a random plane wave superposition. A finite-difference time-domain (FDTD) code is used to compute the material absorbed power and to recover a numerical ACS. The method sensibility is stressed by application to small size samples. Comparison between numerical and experimental data reveals a satisfactory agreement. The simulation technique can be applied to study the absorbing properties of absorbers with arbitrary geometry during the early design stage.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/46259 Collegamento a IRIS

2010 Occurrences of Received Power Anomalous Statistics in Reverberation Chamber
Proceedings of EMC Europe 2010
Autore/i: GRADONI GABRIELE; MARIANI PRIMIANI VALTER; F. MOGLIE; ARNAUT LUK R
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this paper, we present and improve a broad-band statistical analysis of anomalous occurrences inside an electromagnetic reverberation chamber. Besides the traditional Anderson-Darling (AD) test, used as a statistical metric for the distance between theoretical and experimental distributions, we introduce the Pearson system, able to assign a distribution family by knowledge of the first two scale invariants, namely skewness and kurtosis. It is shown that such a system can be used as a test to detect departures of idealized statistics for random fields. In particular, while the AD test is sensitive to low part distortions (as opposite to low values of the support) of the DF, i.e., rejects hypothesis, the Pearson category changes whether right tail is far apart. As a particular case, when both the tests flag out a departure, measured distribution is completely different from the asymptotic one. Upon analysis of the received power, it is found that overmoded regime follows a Pearson type I (beta) or type VI (beta prime) distribution, while undermoded and anomalous occurrences follow a Pearson type IV distribution. This corresponds to a right tail departure and is physically explained by the presence of higher-order coherency, recently predicted by theory.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/46260 Collegamento a IRIS

2010 Evaluation of uncorrelation and statistics inside a reverberation chamber in presence of two independent stirrers
Proceedings of 2010 IEEE International Symposium on Electromagnetic Compatibility
Autore/i: F. MOGLIE; MARIANI PRIMIANI V
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper analyzes the stirrer performances in a reverberation chamber (RC). The independent positions (N) of the stirrers are computed when one or two stirrers rotate inside the chamber. In the case of two operating stirrers, they are moved in both synchronized and interleaved tuned modes showing that this second modality yields a larger independent position number. In the case of one stirrer and two synchronized stirrers, the independent positions are computed using the classical autocorrelation function, whereas in the case of two completely independent stirrers a two dimensional autocorrelation is proposed. It is shown that this procedure does not depend on the order followed to move the stirrers. The stirrer performances are also verified checking the ratio between the maximum and the averaged received power inside the chamber. Finally, the statistics of the received power analyzed applying the severe Anderson Darlington (AD) test to discover the departure from the expected distribution.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/46212 Collegamento a IRIS

2009 Accurate Analysis of Reverberation Field Penetration into an Equipment-Level Enclosure
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: FEDELI D; GRADONI G; MARIANI PRIMIANI V; F. MOGLIE
Classificazione: 1 Contributo su Rivista
Abstract: The paper focuses on the reverberation chamber method for the shielding properties evaluation of equipment-level enclosures. The enclosure under test is numerically modeled by an in-house finite-difference time-domain code that is able to predict the field inside the enclosure and the voltage captured by the probe placed inside it. The chamber fields have been modeled by applying the plane-wave superposition. The code is validated by measurements in our reverberation chamber. Subsequently, the effect of probe positioning and length on the induced voltage is analyzed. Finally, the enclosure shielding effectiveness is evaluated by applying two different definitions, and a statistical analysis is carried out, thus allowing an estimation of the measurement uncertainty.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/52942 Collegamento a IRIS

2009 Numerical and experimental investigation of unstirred frequencies in reverberation chambers
Proceedings of the IEEE International Symposium on Electromagnetic Compatibility, 2009. EMC 2009.
Autore/i: MARIANI PRIMIANI V; F. MOGLIE; PAOLELLA V
Editore: IEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper analyzes the occurrence of unstirred frequencies in a reverberation chamber. Both experimental and numerical field data are checked applying the Kolmogorov-Smirnov test. The presence of these frequencies is unavoidable, even eliminating evident causes. Their value changes introducing small perturbations of the antenna relative position or stirrer starting points in the chamber. In the case of simulated field, based on plane wave expansion, similar unstirred frequencies are still present and their variation are related to the change of the field observation points or of the plane wave set randomly generated.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/52464 Collegamento a IRIS

2009 Densified-Small-Particle (DSP) cement composites for electromagnetic shielding: practice and experimental analysis
Proceedings of EMC Europe 2009 Workshop
Autore/i: R. DE LEO; G. GRADONI; V. MARIANI PRIMIANI; A. MAZZOLI; F. MOGLIE; G. MORICONI
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this work, the shielding effectiveness (SE) of a densified-small-particles (DSP) cement composite, with different loading particles embedded in, has been investigated through the nested reverberation chamber facility. Particular effort has been spent in characterizing the SE behavior with the increasing drying and in improving the experimental practice to solve out previously faced measurement troubles. Findings are of interest in architectural shielding, microwave spectroscopy and investigation of physical-chemical properties of DSP materials.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/47295 Collegamento a IRIS

2009 Carbon based nanomaterial composites in RAM and microwave shielding applications
Proceedings of the 9th IEEE Conference on Nanotechnology, IEEE NANO 2009
Autore/i: D. MICHELI; R. PASTORE; C. APOLLO; M. MARCHETTI; G. GRADONI; F. MOGLIE; V. MARIANI PRIMIANI
Editore: IEEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This work deals with the design of electromagnetic absorber of interest in radar absorbing material (RAM) and microwave shielding systems. This absorber is based on a multilayer structure and the parameters taken into account are: number of layers, absorption maximization, microwave angle of incidence and frequency band. Design and optimization of the absorber are carried out using a Genetic Algorithm (GA) and are based on actual electrical parameters values. Such stochastic method leads to the best trade off between absorption properties and structure thickness, minimizing both the reflection coefficient (RC) and the global multilayer thickness (Thick). All the (carbon based) dielectric materials adopted in GA have been characterized as a function of frequency beforehand and their characteristic impedances inserted in a data base (DB) to be available during design stage. In particular, employed materials consist of epoxy resin reinforced with three different carbon species: micro sized granular graphite, single walled carbon nanotubes (SWCNT) and carbon nanofibers (CNF). The morphology of the multilayer structures is fixed a priori, - i.e., composite material type and its location in the multilayer structure is given - and the stochastic optimization procedure can only decide the best thickness of each layer. Main goals have been achieved and the possibility of realizing a quasi-perfect microwave absorber through graphite and nanomaterials has been demonstrated.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/46737 Collegamento a IRIS

2009 Evaluation of densified with small particles (DSP) cement composite: flexible vs. rigid metal fibers
EUROMAT 2009
Autore/i: MAZZOLI A; G. MORICONI; MOGLIE F; MARIANI PRIMIANI V; DE LEO R
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/43636 Collegamento a IRIS

2009 Investigation of the feasibility of magnetic cardiac stimulation
Abstract collection, joint meeting of the Bioelectromagnetics Society and the European BioElectromagnetics Association 2009
Autore/i: Cerri G.; De Leo A; De Leo R; Della Chiara G; Mariani Primiani V; Moglie F; Pastore A. P; Russo P
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/54142 Collegamento a IRIS

2009 Accuracy Evaluation of the Huygens Subgridding Method
Proceedings of the Progress In Electromagnetic Research Symposium (PIERS)
Autore/i: GRADONI G.; MARIANI PRIMIANI V.; MOGLIE F.
Editore: Electromagnetic Achademy
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this work, an application of the recent Huygens Subgridding (HSG) method to study lossy materials with the ¯nite-di®erence time-domain (FDTD) scheme is presented and a related error analysis discussed. Achieved HSG results showed a good agreement with a full higher-resolution reference guide for di®erent electrical parameter values, indicating a negligible numerical dispersion on the transverse section. Moreover, the increasing decimation factor e®ect has been investigated to evaluate the subgridding accuracy. Findings are of interest in the numerical prediction of planar screens e®ectiveness, material parameters retrieval and microwave spectroscopy.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/50267 Collegamento a IRIS

2009 Field Penetration Through a Wire Mesh Screen Excited by a Reverberation Chamber Field: FDTD Analysis and Experiments
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
Autore/i: V. MARIANI PRIMIANI; F. MOGLIE; A.P. PASTORE
Classificazione: 1 Contributo su Rivista
Abstract: Field penetration into a metallic enclosure with a large aperture protected by a wire mesh screen is analyzed in this paper, using an in-house finite-difference time-domain code with a thin-wire approximation that accurately accounts for the cross between wires of the mesh. All results are experimentally validated using a reverberation chamber. Different enclosure dimensions and mesh sizes are considered, highlighting their implication on shielding performances.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/51393 Collegamento a IRIS


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