Frequency Domain Method for Scattering Damping Time Extraction of a Reverberation Chamber Based on Autocorrelation Functions

The scattering damping time (tau(s)) of a reverberation chamber is a very important parameter but hard to obtain accurately. A novel method for extracting this parameter is presented in this article. By utilizing the frequency domain autocorrelation function and the unstirred frequency domain autocorrelation function, tau(s) can be directly calculated from measured S-parameters without the need of performing the inverse Fourier transform (IFT). Mathematical derivation is given based on the Wiener-Khinchin theorem, and experimental measurements are conducted for different frequency bands as well as different stirrer configurations to verify the proposed approach. Compared with the conventional IFT-based method, the proposed method does not involve the procedure of manually selecting the fitting range, while still maintains advantages in terms of the independence of the radiation efficiency and input impedance of the measurement antennas.