Polarization-Reconfigurable Low-Profile Antenna Array With 2-Bit Phase Resolution for Beam-Scanning Application

In this letter, a polarization-reconfigurable low-profile antenna array with 2-bit phase resolution is proposed for beam-steering applications. A center-fed, center-symmetric patch is proposed to achieve a compact 1-bit multipolar patch design. Fishbone-shaped slots and interdigital capacitors are introduced to optimize impedance matching and far-field radiation. By integrating the radiating element with a 1-bit feed network, the design enables four types of linear polarization (LP) and dual circular polarization (CP) radiation with 2-bit phase resolution, all within a low-profile structure. As each element enables 2-bit phase and polarization reconfiguration, the array’s beam direction and polarization types can be flexibly controlled by adjusting the coding sequence. Based on the 2-bit polarized reconfigurable element, an 8 × 8 reconfigurable 2-bit antenna array is fabricated and tested to verify the beam-scanning performance of the antenna at the polarization of $x$-pol. LP, $y$-pol. LP, $\pm$ 45$^{\circ }$-pol. LP, and dual CP, respectively. The measured results agree well with the simulated results.