A wideband dual-fed circularly polarized antenna

Abstract

A wideband circularly polarized antenna based on dual-polarized magneto-electric dipole antenna is proposed. After connected to a broadband 90° phase shifter and a Wilkinson power divider, the proposed dual-polarized antenna achieves circularly polarized (CP) radiation. This CP antenna exhibits a wide impedance bandwidth of 89.7% from 1.23 - 3.23 GHz with SWR ≤ 2 which covers the whole 3-dB axial-ratio (AR) bandwidth of 82% from 1.28 - 3.05 GHz. In this operation frequency band, the proposed antenna has a broadside gain of larger than 5 dBi above 1.45 GHz. Considering the common overlapped bandwidth limited by the impedance, AR and gain, the proposed antenna exhibits an effective bandwidth of 71%.