Antenna Radiation Efficiency Estimation From Backscattering Measurement Performed Within Reverberation Chambers

TL;DR

This paper introduces a contactless, remote method for estimating antenna radiation efficiency within reverberation chambers, eliminating the need for direct connections and enabling efficient characterization of miniature and embedded antennas.

Contribution

The paper presents a novel non-invasive measurement technique using differential Q-factor analysis with remotely-controlled switches in reverberation chambers.

Findings

Method validated in chambers of 1 m³ and 19 m³ volumes

Efficiency estimates agree well with conventional invasive methods

Suitable for miniature and embedded antenna testing

Abstract

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