A 2-D Circularly Polarized Fixed-Frequency Beam-Scanning Leakywave Antenna for Millimeter-Wave Satellite Communications

A novel 2-D circularly polarized (CP) fixed-frequency beam-scanning leakywave antenna (LWA) is developed. The entire 2-D LWA comprises 16 groove gap waveguides (GGWs), a pair of 1:16 power dividers, and an array of 16\times 24 reconfigurable units. Each unit depends on a corner-cut patch to realize CP properties in millimeter-wave (mm-wave) band. Through the manipulation of PIN diodes loaded in the units, the phase of radiated field of each unit can be switched between two opposite phases (denoted as the "1" state and the "-1" state) with the same radiation strength. By controlling the phase compensation provided by each perturbation unit, a quasi-uniform phase distribution is constructed on the antenna aperture, producing a radiation beam. Subsequently, 2-D beam-scanning at a fixed frequency can be achieved by manipulating the phase distribution. The entire configuration of antenna relies on GGW, contributing to a reduction in dielectric loss in the mm-waveband. The presented antenna is fabricated and measured. The measured peak realized gain of this antenna can reach 20.6 dBic at 33 GHz with good CP characteristic, and the measured results are given to confirm the feasibility of the proposed antenna for mm-wave satellite communication.