Measurement Uncertainty of Antenna Efficiency Measured Using the Two-Antenna Method in a Reverberation Chamber

─ With decades of development, the reverberation chamber (RC) has been proven to be a popular facility to determine antenna efficiency. One-, twoand threeantenna methods have been proposed to measure antenna efficiency without the need of a reference antenna. Due to the stochastic nature of RCbased measurements, the statistical analysis of the uncertainty is indispensable. Recently, the statistical uncertainty models for the oneand three-antenna methods were derived, however, the statistical model for the two-antenna method is still unknown to date. In this paper, the statistical uncertainty model of the twoantenna method is proposed. The approximated relative uncertainty is also given. The derived statistical uncertainty is verified by both simulations and measurements. It is experimentally verified that the statistical model can cope with hybrid stirring and assess the measurement uncertainty with and without frequency stirring in an efficient and convenient way. Index Terms ─ Antenna efficiency, measurement uncertainty, reverberation chamber, two-antenna method, hybrid stirring.