Three-Beam Circularly Polarized ME Dipole Antenna Array Fed by 3 × 3 Butler Matrix

Abstract

A circularly polarized array consisting of magneto-electric (ME) dipole antennas with beam scanning is proposed, which is fed by a substrate integrated waveguide (SIW) 3 × 3 butler matrix. The wide AR beamwidth antenna element is the key to completing the antenna array. In order to ensure the generation of normal beam, the 3 × 3 butler matrix was adopted as the beam-forming network. The proposed structure operates in the range of 27.5GHz ~ 28.5GHz and generates three circularly polarized beams that cover the range of ±40°.