Chamber influence estimation for radiated emission testing in the frequency range of 1 GHz to 18 GHz

The paper presents a comprehensive analysis of the behavior of anechoic chambers in the frequency range from 1 GHz to 18 GHz. Numerical simulation and statistical analysis have been used to estimate the influence of the test site to radiated emission results above 1 GHz. For typical EMC chambers, the influence factor is around 0.7 dB. This factor can be improved by using better absorbing material or by increasing the chamber size. For a wide range of EUTs, the compliance uncertainty can be estimated using the chamber influence factor. The prediction of the chamber influence for small omnidirectional EUTs fits very well. Small EUTs with a directive disturbance source are overestimated. Large EUTs with multiple sources have not been investigated.