Acceleration Technique of Modeling Lossy Reverberation Chamber Using FDTD Method Based on Quality Factor

Abstract

Aiming at accelerating the simulation of the lossy reverberation chamber using the finite-difference time-domain method, a fast and accurate approach is proposed. The lumped losses of the real chamber are equivalently substituted by adding the artificial-loss atmosphere, which is evenly distributed throughout the chamber. Unlike the lumped loss, such even loss could reduce the simulation time dramatically. The conductivity of such medium is evaluated on the basis of the quality factor of the reverberation chamber, which is generally deemed as the capability of composite losses, rather than by manual attempts or experience. As examples, two different sorts of excitations are simulated to validate the correctness and generality of the artificial-loss technique. Index Terms-Finite-different time-domain (FDTD), quality factor ( ) , reverberation chamber.

Evaluation of equivalent conductivity of reverberation chambers wall

“…Obviously, the numerical results with the aforementioned conductivity settings still overestimate the Q factor, especially for the low frequencies (below 1 GHz). Indeed, as discussed in [7,8], the multiple reflections of incident waves over a complex iron-zinc structure account for significantly lower conductivity than zinc.…”

“…Whereas for time-domain method, it mainly concentrates on the time constant τ, relying on the impulse response of the chamber [6,7]. And thus, for a given frequency, Q factor can be easily derived by τ, which will be more precisely estimated if the loading caused by antennas and other configurations has been eliminated [8,9]. Theoretically, both frequencyand time-domain methods can obtain the similar Q factor.…”

A Fast Finite-Difference Time Domain Simulation Method for the Source-Stirring Reverberation Chamber

“…Adding some lossy objects or materials to the chamber can make the electromagnetic signal in RCs attenuate more quickly, but excessive loads in the chamber could degrade the field uniformity and field level, which makes the performance of the chamber unacceptable. Another way to accelerate the simulation of RCs is adding artificial loss to the volume inside the chamber [16], but parameters such as conductivity of the medium inside the cavity used in this method are frequencydependent. If the wide-band result is required, the FDTD iteration has to be conducted repeatedly with the parameters averaged in different narrow bands.…”