Conference Agenda

One possible method for characterising the electric field in a reverberation chamber in the frequency domain is the superposition of plane waves. However, for signals such as single carrier pulses, the appearance of peaks in the transient part of the signal has been observed. The presence of these peaks gives rise to significant challenges during immunity testing, as there is a risk of obtaining transient electric field values that exceed the steady-state. A transient plane wave representation is used to describe the behaviour of the electric field inside a reverberation chamber as a sum of plane waves with random amplitude, direction and phase shift in space. A mathematical model is presented to calculate the electric field generated in the chamber and the results obtained for different frequencies are compared with those obtained in the measurements.

This paper introduces a method for evaluating electrical fields in Reverberation Chambers (RCs) using the Chi distribution. The approach is particularly useful for estimating the Lowest Usable Frequency (LUF) of a given RC and its configuration. The LUF estimate includes the effects of correlation between electric field components, isotropic properties, and homogeneity by comparing measured values to theoretical predictions from the Chi distribution. An expected limit is also proposed to determine whether the RC demonstrates sufficient homogeneity, isotropy, and uncorrelated field components, or if the stirring process needs improvement. The method is applied to estimate the LUF of two different RCs.

The quality factor (Q-factor) is a key parameter for assessing the performance of reverberation chambers (RCs) and plays also a fundamental role in some EMC or antenna measurements (e.g. shielding effectiveness). In this paper we address its experimental estimation in situations where no mechanical stirrer is available or used. Several strategies are introduced and illustrated to perform unbiased estimations based on scattering parameters acquisition and frequency sweep only.

This paper investigates the effect of different stirring strategies on the estimation of field homogeneity in mode-stirred reverberation chambers. Field homogeneity is one of the fundamental properties of field uniformity in reverberation chambers, and the study of factors that influence it is of crucial importance. By comparing measurements from two different stirring strategies in mode-stirring operation and confronting them with mode-tuned operation, we demonstrate that field homogeneity appears worse when the stirrer is rotated in an asynchronous (i.e. not zeroed and not timed) fashion. An alternative definition of field homogeneity together with a multivariate random variable approach helps attribute this phenomenon to high (apparent) correlations that predict a fictitiously low effective sample size. The findings underscore the importance of considering the stirring strategy in mode-stirred reverberation chamber measurements.