A low-profile broadband antenna for wireless communications

A low-profile microwave antenna suitable for high data-rate radio communications is presented. Although the size, cost, and efficiency are comparable to the microstrip patch, the 2:1 VSWR bandwidth of the antenna exceeds 20%. The radiation pattern of the antenna does not change appreciably within the bandwidth, and the efficiency remains above 70% within the bandwidth. Measurements on antennas around 2 and 4 GHz are presented as well as theoretical results using a full-wave analysis.