Beamwidth-Enhanced Circularly Polarized Antenna Using Non-Uniformly Compressed High-Order Mode Dipoles

Abstract

A circularly polarized (CP) antenna with enhanced axial-ratio and half-power beamwidths (HPBWs) using nonuniformly compressed high-order mode dipoles is proposed in this article. First, wide HPBW at E-plane is obtained by a third-mode dipole with proper nonuniform compressed parameters. Then, a crossed nonuniformly compressed high-order mode dipole is proposed, and wide axial-ratio beamwidths (ARBW) and HPBWs are both achieved in two orthogonal planes. Next, a S-shaped CP antenna based on nonuniformly compressed high-order mode dipoles is presented with wide beamwidths in all cut-planes in the upper hemisphere. Finally, the antenna is fabricated and measured to verify the design. The measured results show that the HPBWs are larger than 109° and ARBWs are larger than 118° in eight cut-planes.