A Bidirectional Fabry–Pérot Cavity Antenna with Flat-Top and Pencil Beam Integration for Millimeter Wave Applications

This paper proposes a bidirectional Fabry–Pérot Cavity (FPC) antenna with flat-top and pencil beam integration. It is the first attempt to propose a structurally shared reflector (SSR) for bidirectional FPC antenna. The SSR contributes to phase and magnitude manipulation for bidirectional beams, respectively. For the generation of the flat-top beam, the SSR acts as a reversely curved ground. For the generation of the directive/pencil beam, the SSR functions as a quasi-curved ground, enabling an in-phase field distribution in the backward radiation direction. In addition, by exciting multiple resonant modes and manipulating their phase distributions on back radiation aperture, the gain level and bandwidth can be enhanced. For verification, an antenna prototype based on the above design principles is designed, fabricated and measured. It achieves an overlapped impedance matching bandwidth from 28.65 GHz to 31.45 GHz for both radiation states. It yields a peak gain of 19.36 dBi in pencil beam state. For flat-top beam state, a 3-dB beamwidth of 120 deg and a peak gain of 9.24 dBi are achieved. The gain fluctuation within bandwidth is less than 1 dB. It is a good candidate for millimeter wave communication scenarios such as the satellite-air-ground integrated networks (SAGIN). © 1963-2012 IEEE.