Shorting posts loaded patch coupler with enhanced bandwidth and extended coupling coefficient range

摘要

This article presents a thorough investigation of the use of shorting posts to widen the bandwidth and coupling coefficient range of a patch quadrature coupler. The lumped equivalent circuit is used to analyze the characteristics of two proposed shorting posts loaded patch configurations. It is shown that by loading shorting post on the center of a patch, the bandwidth of coupler with loose coupling can be significantly improved. The patch configuration with four shoring posts is also proposed to provide a loose coupling coefficient up to 15 dB, which cannot be achieved using the conventional configuration. For demonstration purposes, two quadrature couplers were designed to exhibit 10 and 15 dB coupling coefficients with bandwidths of 29 and 19.2, respectively. (c) 2016 Wiley Periodicals, Inc.