A Transmissive Wideband Linear-to-Circular Polarization Converter Based on 90° Phase Shifter

A wideband linear-to-circular polarization converter (LCPC) with 90° phase shifter is presented in this conference. A 45°-polarized plane wave can be decomposed into a horizontally polarized wave and a vertically polarized wave with equal amplitude and identical phase. With the designed phase shifter, the proposed polarization converter can produce a 90° phase difference between the transmitted horizontally and vertically polarized wave while preserving a consistent amplitude, resulting in a circularly polarized (CP) wave. The simulated results show that the proposed polarization converter exhibits a 3-dB axial ratio (AR) bandwidth of 90.4% from 1.68 GHz to 4.45 GHz. It also reaches a high power transmission ratio (PTR) from 1.89 GHz to 3.90 GHz.