Microstrip Antennas, Broadband

Abstract

With <1% in bandwidth, the first microstrip patch antenna has limited applications, mainly for defense purposes. With tremendous effort dedicated to the bandwidth enhancement of microstrip antennas, they are now becoming the most popular antennas selected for modern wireless communications. This article collects different approaches for enhancing the bandwidth of microstrip antennas, including the stacked‐patch, U‐slot patch, and L‐probe coupling techniques. Emphasis is placed on the L‐probe technique, which is demonstrated to be attractive for the development of wideband dual‐polarized patch antennas, and wideband miniature patch antennas for state‐of‐the‐art mobile communications. Throughout the article, design guidelines and principles of operation for most of the designs are highlighted.