2017 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2017
Reverberation chambers are successfully adopted to test last generation wireless communication sy... more 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.
2014 International Symposium on Electromagnetic Compatibility, 2014
A method for estimating the number of independent stirrer positions in reverberation chambers is ... more 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.
2014 IEEE International Symposium on Electromagnetic Compatibility (EMC), 2014
ABSTRACT Fourth generation (4G) cellular systems have been nowadays rolled out already in several... more 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.
2014 International Symposium on Electromagnetic Compatibility, 2014
Performances of reverberation chambers exhibit a non-trivial dependence on distributed losses. It... more 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.
2014 IEEE International Symposium on Electromagnetic Compatibility (EMC), 2014
Finite-difference time-domain simulations of reverberation chambers exhibit a strong frequency de... more 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.
IEEE International Symposium on Electromagnetic Compatibility, 2009
The paper investigates the effects of the voltage on the antenna caused by a multipath propagatio... more The paper investigates the effects of the voltage on the antenna caused by a multipath propagation environment. This type of environment was reproduced by a reverberation chamber. Both scattered and direct components were considered for the excitation of the receiving antenna, ranging from line-of-sight to non-line-of-sight 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.
IEEE International Symposium on Electromagnetic Compatibility, 2010
Page 1. Evaluation of Uncorrelation and Statistics Inside a Reverberation Chamber in Presence of ... more Page 1. Evaluation of Uncorrelation and Statistics Inside a Reverberation Chamber in Presence of Two Independent Stirrers Franco Moglie #1, Valter Mariani Primiani #2 # DIBET, Universit`a Politecnica delle Marche Via Brecce ...
IEEE International Symposium on Electromagnetic Compatibility, 2011
... [6] A. Coates, HG Sasse, DE Coleby, AP Duffy, and A. Orlandi, “Validation of a three-dimensio... more ... [6] A. Coates, HG Sasse, DE Coleby, AP Duffy, and A. Orlandi, “Validation of a three-dimensional transmission line matrix (TLM) model implementation of a mode-stirred reverberation chamber,” IEEE Trans. Electromagn. ... 214–221, Feb. 2002. [9] J. Clegg, AC Marvin, JF Dawson ...
IEEE International Symposium on Electromagnetic Compatibility, 2012
ABSTRACT The paper analyzes the performance of a reverberation chamber equipped by a “carousel” s... more 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.
2017 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2017
Reverberation chambers are successfully adopted to test last generation wireless communication sy... more 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.
2014 International Symposium on Electromagnetic Compatibility, 2014
A method for estimating the number of independent stirrer positions in reverberation chambers is ... more 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.
2014 IEEE International Symposium on Electromagnetic Compatibility (EMC), 2014
ABSTRACT Fourth generation (4G) cellular systems have been nowadays rolled out already in several... more 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.
2014 International Symposium on Electromagnetic Compatibility, 2014
Performances of reverberation chambers exhibit a non-trivial dependence on distributed losses. It... more 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.
2014 IEEE International Symposium on Electromagnetic Compatibility (EMC), 2014
Finite-difference time-domain simulations of reverberation chambers exhibit a strong frequency de... more 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.
IEEE International Symposium on Electromagnetic Compatibility, 2009
The paper investigates the effects of the voltage on the antenna caused by a multipath propagatio... more The paper investigates the effects of the voltage on the antenna caused by a multipath propagation environment. This type of environment was reproduced by a reverberation chamber. Both scattered and direct components were considered for the excitation of the receiving antenna, ranging from line-of-sight to non-line-of-sight 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.
IEEE International Symposium on Electromagnetic Compatibility, 2010
Page 1. Evaluation of Uncorrelation and Statistics Inside a Reverberation Chamber in Presence of ... more Page 1. Evaluation of Uncorrelation and Statistics Inside a Reverberation Chamber in Presence of Two Independent Stirrers Franco Moglie #1, Valter Mariani Primiani #2 # DIBET, Universit`a Politecnica delle Marche Via Brecce ...
IEEE International Symposium on Electromagnetic Compatibility, 2011
... [6] A. Coates, HG Sasse, DE Coleby, AP Duffy, and A. Orlandi, “Validation of a three-dimensio... more ... [6] A. Coates, HG Sasse, DE Coleby, AP Duffy, and A. Orlandi, “Validation of a three-dimensional transmission line matrix (TLM) model implementation of a mode-stirred reverberation chamber,” IEEE Trans. Electromagn. ... 214–221, Feb. 2002. [9] J. Clegg, AC Marvin, JF Dawson ...
IEEE International Symposium on Electromagnetic Compatibility, 2012
ABSTRACT The paper analyzes the performance of a reverberation chamber equipped by a “carousel” s... more 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.
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