A Low-Profile and Dual-Linearly Polarized Programmable Array Antenna for 2-D Wide-Angle Scanning

This paper demonstrates a low-profile, dual-linearly polarized programmable array antenna with two-dimensional (2-D) wide-angle beam-scanning capability. A polarization reconfigurable crossed bow-tie patch is proposed, where PIN diodes are employed to precisely control the distribution of surface current path, enabling flexible switching between two orthogonal linear polarization. When integrating with phase shifters, each radiating element can achieve eight discrete phase coding states with a 45° interval in both polarization modes, thus enabling wide-angle beam steering. To validate the proposed design, an 8×8 prototype operating at 10 GHz with a thickness of 0.09λ0 is fabricated and characterized. Experimental results demonstrate maximum gains of 18 dBi and 18.1 dBi for x- and y-linearly polarized mode, respectively, corresponding to an aperture efficiency of 38.7% and 39.6%, and the cross-polarization levels are below -30 dB. Both polarization modes exhibit the same 3-dB gain bandwidth of 15.8%. Additionally, wide-angle beam scanning of ±55° × ±55° is achieved with less than 3.5 dB gain variation across the scanning range. The proposed dual-linearly polarized programmable array antenna, offering a wide-angular 2-D beam-steering capability with polarization agility, is expected to find applications in future wireless communication and radar system.