Determination of Antenna Radiation Efficiency Using the Reference Waveguide to Coax Adapter Method in a Reverberation Chamber

A simple technique based on the substitution method is proposed to measure the radiation efficiency of an antenna in a re-verberation chamber. The substitution method requires a reference antenna with a known radiation efficiency, which is composed of ohmic and dielectric losses and is usually difficult to measure. In the proposed method, a waveguide to coax adapter is used as the reference antenna. The radiation efficiency of this adapter can be easily and accurately measured as insertion loss by connecting it directly to a vector network analyzer. The radiation efficiency of a WR-42 pyramidal horn antenna with the frequency band of 18 GHz to 26.5 GHz was determined by the proposed method.