Printed Ridge Waveguide-Fed Dual-Circularly Polarized Shared-Aperture Array for K- and Ka-Band Satellite Communications

In this paper, a dual-band dual-circularly polarized (CP) shared-aperture array is proposed. The array consists of two 2×2 substrate integrated waveguide (SIW) slot subarrays which can achieve the right-hand CP (RHCP) radiation around 20 GHz and the left-hand CP (LHCP) one around 30 GHz, respectively. Two kinds of sequentially rotated feeding networks using the printed ridge gap waveguide (PRGW) are designed to further improve the axial ratio (AR) bandwidths in both bands. The designed array is simulated and analyzed. It features that the array possesses the -10-dB impedance bandwidths of 11.7% and 11.3%, and 3-dB AR bandwidths of 8.8% and 8.3% in the lower and upper bands, respectively. Besides, the isolation between dual ports is higher than 25 dB.