A Circular-Polarization-Reconfigurable Holographic Leaky-Wave Antenna With Fixed-Frequency Beam-Scanning Property

A fixed-frequency beam-scanning leaky-wave antenna (LWA) with circular-polarization (CP) reconfigurable property operating in Ka band is developed in this letter. A groove gap waveguide (GGW) structure is adopted for feeding and transmission, and 64 CP patches are excited through the cross-shaped slots etched over the GGW. By switching the conditions between "ON" and "OFF" of the PIN diodes, these exciting slots can act as either transverse slots or longitudinal slots, and hence to realize the transition between left-handed circular polarization (LHCP) and right-handed circular polarization (RHCP). Meanwhile, the fixed-frequency beam-scanning characteristic is achieved by manipulating the hologram, which is controlled by the activation states of diodes. Finally, the presented fabrication is taken into experiment to verify its performance, and an agreement can be observed in the simulated and experimental results. The eventual peak gains reach 13.4 dBic in the LHCP state and 12.1 dBic in the RHCP state, respectively. In addition, a beam-scanning range up to 100 degrees between -50 degrees and 50 degrees is realized with desirable CP reconfigurable performance between LHCP and RHCP.