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

In this paper, 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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$x$</tex-math></inline-formula>-pol. LP, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$y$</tex-math></inline-formula>-pol. LP, ± 45°-pol. LP, and dual CP, respectively. The measured results agree well with the simulated results.