Antenna Radiation Efficiency Estimation From Backscattering Measurement Performed Within Reverberation Chambers

This paper presents a contactless measurement method for antenna radiation efficiency estimation within reverberation chambers (RCs). does not require to connect any analyzer the under test (AUT). The AUT is obtained from differential of RC composite $Q$-factor estimated two load conditions, namely an open circuit and \SI[detect-weight]{50}{\ohm} load. Remotely-controlled RF switches are used in order keep setup identical both measurements. experimentally validated RCs different volumes (1~m$^3$ 19~m$^3$) with wideband patch 1.8~GHz 2.8~GHz frequency range. found be very good agreement one through conventional invasive technique. new suitable miniature buried characterization without access its port.