Broadband Antenna Radiation Pattern Measurement From Backscattering Coefficient in a Reverberation Chamber

This paper deals with the contactless measurement of the radiation pattern of a log-periodic antenna within a reverberation chamber (RC). This method relies on backscattering measurement, i.e., avoiding to connect the antenna under test (AUT) to any analyzer, for two distinct AUT load conditions. The post-processing is based on a sinusoidal regression applied on the difference between the reflection coefficients measured for the two load conditions. A critical parameter to estimate is the frequency of the sinusoidal regression that depends here on the distance between the measurement antenna and the AUT. It is shown in this paper that the variation of the antenna phase center as a function of frequency has to be taken into account.