Comparison of Cavity-based Ultra Wideband Antenna Efficiency Measurement Methods

This article reviews the family of Ultra Wideband (UWB) antenna radiation efficiency measurement methods com- monly known as the UWB Wheeler cap. Measurement results of one UWB and two narrowband antennas are compared with the recently introduced source-stirred generalized UWB Wheeler cap (SS-GWCM) which is based on a different approach. It was found that all techniques yield similar radiation efficiency results for an UWB prototype. The results differ for the two tested narrowband prototypes. Therefore, for antenna radiation efficiency, this family of approaches might not provide satisfactory results. The possible reasons for the differences are also discussed numerically. It was confirmed that the novel SS-GWCM provides antenna radiation efficiency results closer to simulations.