Dual Band Low Profile Circular-Polarized Shared Aperture Phased Array for Satellite Communication

This paper proposes a low-profile, shared aperture antenna suitable for low Earth orbit satellite communication, operating in the dual-frequency bands of left-hand circular polarization (LHCP) at 21 to 22 GHz and right-hand circular polarization (RHCP) at 25 to 27 GHz. The dual cross-band isolations are better than 20dB and 25dB. The dualband shared aperture array is arranged in an equidistant square pattern. The total profile is only 0.762mm, about 0.06 high-frequency wavelengths. A wide-angle scanning of $\pm 60^{\mathrm{o}}$ is obtained in both operating bands, and the axial ratio is always below 3dB during scanning.