A Millimeter-Wave Circular-Polarization-Reconfigurable Leaky-Wave Antenna with Fixed-Frequency Beam Scanning Based on Phase Control

This article presents a fixed-frequency beam-scanning leaky-wave antenna (LWA) that relies on phase control to achieve beam steering and reconfigurable polarization in millimeter-wave (mm-wave) band. The entire antenna is comprised of an air-filled groove gap waveguide and 64 reconfigurable polarization perturbation unit, facilitating the transition between left-handed circular polarization (LHCP) and right-handed circular polarization (RHCP). Each unit is equipped with four PIN diodes, enabling the switching of polarization states and radiated phase states. Through simulation and experimental verification, the designed LWA demonstrates a large scanning range, covering from backward -45° to forward 50° in both LHCP and RHCP. The measured peak realized gain attains 15.4dBic for LHCP and 15.6dBic for RHCP. Additionally, the axis ratios of majority scanning beams remain below 3dB, showing good circular polarization characteristics. The polarization reconfigurable LWA has potentials in the field of mm-wave wireless communication.