Comparison of Broadband Signals in Reverberation and Semi Anechoic Chambers

Beside the radiated immunity test with continuous wave signals, devices might also react to other excitations, e.g. band limited white noise signals. For this purpose, an anechoic chamber appears to be an evident testing environment for broadband immunity, because these signals do not get distorted by the properties of the chamber. In comparison, reverberation chambers offer some advantages for immunity tests, making it a desirable alternative environment. However, the reverberation chamber builds up on statistical processes, so the reflections at the walls lead to significant distortions of the excitation signal. This work presents a comparison of the electromagnetic fields inside a semi anechoic and a reverberation chamber with regard to the resulting distortion when excited with band limited white noise signals with center frequencies at 250 MHz, 600 MHz and 950 MHz, each with a bandwidth of 100 MHz.