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Angular Spectrum for Wireless Over-the-Air Measurements in the Loaded Reverberation Chamber

Reverberation chamber (RC) plays a very important role in the over-the-air (OTA) test of wireless devices. This work researches the power-angle-frequency spectrum and the power-angle-delay spectrum of the directional antenna under test (AUT) in the loaded RC. Through the derivation and measurement, it can be verified that, compared with the angular spectrum under a single scanning radius, synthetic aperture angular spectrum under multiple groups of different radii can more clearly reveal the relationship between the received power of directional AUT and the changes of azimuth angles and time delays, reflecting the spatial and temporal characteristics of the channel in the chamber. Meanwhile, the experimental results show that the absorbing loads can provide anisotropic channel environment and economic OTA solutions for the wireless devices with beamforming ability.