Emmanuel Amador

On the

Reverberation chambers were recently proposed to simulate Rician radio environment with controllable K-factor. The K-factor is also a parameter that may tell how ideal may be a reverberation chamber when it is used for other more conventional purposes. This paper is dedicated to the problem of the correct estimation of K in a reverberation chamber given a set of data measured along a stirring process.

K

In this paper, we propose a straightforward 3-D time-domain model of a reverberation chamber (RC) based on image theory. This model allows one to describe the earliest moments of an arbitrary waveform in an RC. Time domain and frequency domain results from this model are analyzed and compared with measurements conducted in a RC.

-Factor Estimation for Rician Channel Simulated in Reverberation Chamber

We propose a statistical analysis of immunity testing in EMC based on binomial distributions. This approach aims at extracting the immunity properties of a device from its probability of failure during a test. We show that under certain conditions, this approach can be applied to plane wave testing environments and reverberation chambers. This approach allows one to control the uncertainty of the immunity level estimation and to reduce the duration of a test by both reducing significantly the number of observations needed to reach a given uncertainty budget and giving an optimal number of power level tested. We show the benefits of such an approach for immunity testing and we present some experimental results.

Reverberation Chamber Modeling Based on Image Theory: Investigation in the Pulse Regime

Reverberation chambers are well known for providing a random-like electric field distribution. Detection of directivity or gain thereof requires an adequate procedure and smart post-processing. In this communication, a new method is proposed for estimating the directivity of radiating devices in a reverberation chamber (RC). The method is based on the Rician K-factor whose estimation in an RC benefits from recent improvements. Directivity estimation relies on the accurate determination of the K-factor with respect to a reference antenna. Good agreement is reported with measurements carried out in near-field anechoic chamber (AC) and using a near-field to far-field transformation.

A Binomial Model for Radiated Immunity Measurements

In this article, a numerical model based on a physically accurate combination of the cavity modes of a reverberation chamber is presented. This new model allows to compute the E-field in the reverberation chamber volume and to get the magnitude coefficient of every excited mode for a given transmitter position. These mode coefficients give a precious information on how the modes are combined in the cavity when a transmitter is moving (source stirring). Then, we try to find a relation between the number of independent source positions and the number of modes excited in the cavity during the source stirring process. Different source stirring configurations are studied and discussed in comparison with mechanical stirring. Future usages of this numerical model are discussed.

Antenna Directivity Measurement in Reverberation Chamber From Rician

This paper proposes for the first time a method for estimating the gain of an antenna in a mode-stirred reverberation chamber. The method is based on the estimation of the Ricean K-factor which provides the relative transmitting power level of the line-of-sight path. Experimental results are compared with anechoic chamber measurements using a set of different antennas.

K

Wireless devices have been massively developed in recent years, creating a real need to simulate controllable multi-path channels. Reverberation chamber is a well-known cavity for electromagnetic compatibility (EMC) testing and knows an increasing interest for wireless communication testing. In particular, it enables to generate various measurements distributions from Rayleigh to Rician. In order to estimate correctly direct and scattered components of a transmitted signal in RC, we propose two new methods leading to an accurate evaluation of the direct-to-scattered ratio (DSR).

-Factor Estimation

In this article, we propose a time-domain model of a reverberation chamber (RC). This very straightforward model based upon image theory (IT) allows to simulate the behavior of a reverberation chamber in the pulse regime. After a brief introduction of the model, results with different pulse lengths and different loading configurations are presented and compared to measurements made in the reverberation chamber of our laboratory.