A Compact Dual-Band Circularly-Polarized Antenna with Wide Axial-Ratio Beamwidth

Abstract

A compact circularly-polarized patch antenna with wide axial-ratio beamwidth (ARBW) operating at dual bands is proposed in this paper. The antenna consists of two stacked patches, which account for GPS L ₁ band (1575 ± 2 MHz) and L ₂ band (1228 ± 2 MHz). In the proposed antenna, four pillars are introduced to realize miniaturization. To adjust the beamwidth response of the far-field components, the antenna is backed by a modified metallic cavity, which in turn widen the 3-dB axial ratio beamwidth (ARBW) at two operating bands effectively. Finally, the proposed design with excellent performance is realized in a size of 0.368 λ ₀ (diameter) and 0.105 λ ₀ (height). Simulated and measured results show that the ARBWs at L ₁ and L ₂ bands are as wide as 173° and 133°, respectively.