Low Profile Unequally Dual-Feed Circularly Polarized Patch Antenna with a Wide Beamwidth

摘要

In this paper, a compact dual-feed wide-beam circularly-polarized (CP) microstrip patch antenna is presented. The proposed antenna comprises a conventional probe-feed circular patch etched by two rectangular notches to generate CP operation. An independent probe-feed coplanar and concentric annular ring is introduced to achieve a broad half-power beamwidth (HPBW) and low profile property simultaneously. Besides, the substrate size is increased to further widen the HPBW. The proposed antenna has a low profile of 0.027 λ0. When the inner patch and outer ring are fed with a power ratio of 1:5, the simulated 3-dB beamwidth is approximately 191° at the center frequency of 2.5 GHz, covering the entire upper half space, which is more than twice of its conventional counterpart.