Reflect–Transmit-Array Antenna With Independent Dual Circularly Polarized Beam Control

In this letter, we propose a dual circularly polarized reflect–transmit-array (RTA) antenna with independent beam control. It can transmit left-hand circularly polarized (LHCP) wave as transmitarray antenna and reflect right-hand circularly polarized (RHCP) wave as reflectarray antenna at 8.7–10.2 GHz. In addition, 360° phase shift for each circularly polarized wave can be achieved by rotating the top and bottom patches. A 20 × 20-unit cell RTA is designed, fabricated, and measured. For the LHCP radiation, the measured results show that the 3 dB gain bandwidth and axial ratio (AR) bandwidth are 13.7% (8.8–10.1 GHz) and 15.9% (8.7–10.2 GHz), respectively. For the RHCP radiation, the measured 3 dB gain bandwidth and AR bandwidth are 11.4% (9.1–10.2 GHz) and 12.6% (8.9–10.1 GHz). The peak aperture efficiencies for LHCP and RHCP radiations are 45.5% at 9.2 GHz and 41.8% at 9.6 GHz, respectively.