A Metasurface-Based Multilayer Wideband Circularly Polarized Patch Antenna Array With a Parallel Feeding Network for Q-Band

In this letter, a metasurface (MS)-based multilayer wideband circularly polarized (CP) 4 x 4 truncated corner patch antenna array is proposed for Q-band applications. The patch array consists of four 2 x 2 patch subarrays, an MS structure, and an H-shaped substrate integrated waveguide power divider. Each 2 x 2 patch subarray acts as the CP radiating element, which is fed by a compact parallel-fed microstrip power divider using a sequential rotation technology. The MS structure has 4 x 4 square plates covering over each patch to improve |S-11|, axial ratio (AR), and gain performances. The antenna was fabricated and measured to verify the practical feasibility. -10 dB | S-11| bandwidth of 32% (37.4-52.2 GHz), 3 dB AR bandwidth of 25.8% (39.2-51.5 GHz), 3 dB gain bandwidth of 27.6%, and the peak gain of 18.2 dBic are achieved in the vicinity of 45 GHz.