Conference Agenda

We present a detailed study of short versus long pulses in reverberation chambers (RC). Understanding their behaviour in RC should contribute to reliable EMC testing with pulsed signals. To this end, we analyse amplitude and shape of pulses averaged over stirrer positions as a function of chamber loading for different frequencies. While the amplitude essentially corresponds to theoretical expectations, there are unexpected features in the shape especially for short pulses.

This paper aims at improving the lowest usable frequency (LUF) of a mode-stirred chamber. To characterize a standard-sized chamber, a 5:1 scaled-down chamber is designed to simplify testing of modifications to the chamber. In the proposed method, varactor tuned resonators are used in the mode-stirred chamber to generate additional modes at frequencies between the first resonant mode and the LUF, where the chamber has a low mode density. This method can be used for emission measurements of a device under test (DUT). The field homogeneity in the working volume of the scaled-down chamber is measured mainly from 400 MHz to 1000 MHz (actual chamber: 80 MHz to 200 MHz).

Mode stirrers are typically used to change the boundary conditions when performing measurements in reverberation chambers (RCs). A major concern arises in determining the number of independent realizations or, equivalently, the effective sample size (Neff) obtained during stirrer rotations. A significant effort has been put into determining the effective sample size in the literature, leading to the proposal of numerous methods. However, those methods yield different estimations for Neff, which does not allow a clear diagnosis. This paper aims to provide an empirical estimation based on the average of the standard deviation over the mean estimation in relation to the central limit theorem (CLT). It is confronted with different theoretical models in the literature. Finally, it is confirmed that the spatial correlation of data series provides a better estimation than all other methods.

Accurate characterization of electromagnetic radiation from electrical devices in the cm-wave frequency bands is more important than ever given the proposed extension of the 6G spectrum in the 7-15GHz frequency range and continued use of the 8-12GHz band. This paper enables measurements from 8GHz to 12GHz within a tabletop reverberation chamber with a maximal electrical size of 32λ. Total radiated power measurements show that good field uniformity is achieved in the chamber as indicated by a standard deviation of the chamber transfer function of less than 0.40dB across the entire range. The chamber decay time is at all times above 0.10μs and shows large similarity between measurement realizations. Antenna efficiency is shown to be accurately estimated, provided that the antennas are directed away from the stirrers.

Reverberation chambers serve a critical function in assessing the performance of wireless communication systems by providing controlled testing environments. A key aspect of this evaluation is the manipulation of the Rician K-factor within these chambers. The primary challenge arises from the inherently low values of the Rician K-factor, which require deliberate adjustments to accurately simulate real-world communication conditions.

Traditionally, the tuning of the Rician K-factor involves the introduction of lossy elements, which decrease the quality factor of the chamber and necessitate additional costs for amplification to sustain the desired electromagnetic field intensity. An alternative approach focuses on the selection of electromagnetic states within the chamber, which does not significantly alter the field amplitude but may affect its statistical properties. The proposed method represents a trade-off between these two strategies, enabling a reduction in amplification costs while preserving the statistical property of the electromagnetic field distribution to remain Rician.

This method has been successfully implemented across different chamber configurations and has been explored in various frequency ranges.