Antenna radiation pattern measurements in reverberation chamber using Doppler analysis

Reverberation chambers (RC's) are electrically large, highly conductive resonant enclosures used as test facility for radiated emissions and immunity measurements on electronic devices. In literature, it is commonly stated that antenna radiation patterns cannot be measured, if needed, in RC. On the contrary, in this contribution, a novel technique that allows to perform actual antenna radiation pattern measurements in RC is presented. Stationary measurements are performed by locating the antenna under test (AUT) at N different fixed positions along its line-of-sight to a fixed probe antenna per angle under study, and making use of plane wave decomposition and a spatial Doppler analysis, the Doppler power spectral density is obtained, and eventually, the AUT radiation pattern. In order to demonstrate its validity, the radiation pattern for both E- and H-planes of a horn antenna has been measured in an RC at 10 GHz, in X band, and compared to the ones obtained in anechoic chamber, being the results in good agreement. Moreover, an improvement of this technique is presented, which could permit to obtain an antenna radiation pattern by performing only one measurement per angle under study, taking advantage of realtime Doppler effect.