Circularly-Polarized and High-Efficiency Microstrip Antenna with C-Shaped Stub for WLAN and WiMAX Applications

Abstract

In this article a novel planar triple-band microstrip monopole antenna with circular polarization and high efficiency is presented for wireless communications applications. This antenna with passbands at 2.4, 3.5, and 5.5 GHz is able to cover WLAN and WiMAX applications according to the IEEE 802.11b/g and IEEE 802.16 standards. The proposed antenna consists of a C-shaped stub to control the circular polarization and an inverted triangular patch which has two slots to achieve mentioned frequency bands. The proposed monopole antenna with dimensions 40×47×1.6 mm is implemented on the FR4 substrate and fed by a 50 Ω microstrip line. Parametric study for antenna dimensions and measurement results are presented in the article. The S-parameters of less than −10 dB, efficiency above 90% and omnidirectional radiation patterns are obtained in the proposed antenna. A brief comparison is made on the characteristics of the proposed antenna and other antennas presented in the articles and the results are presented.