Design of a High-Gain Duplex Antenna With Multibeam Radiation Based on a Fabry-Pérot Cavity

A high-gain duplex antenna with multibeam radiation based on a Fabry–Pérot Cavity (FPC) is proposed in this paper. For the performance, it is the first FPC antenna integrated with duplex and multi-beam radiation. It is the first endeavor to apply a wideband FPC to a duplex antenna with two channels, aiming at significantly enhancing their realized gains and subsequently achieving three switchable directive beams. Firstly, a low-profile duplex slot antenna with two isolated channels (9.4 and 10.7 GHz) is designed. Then, to enhance the realized gains for two channels simultaneously, a wideband FPC with a stepped reflective ground is designed and combined with the proposed duplex slot antenna. The upper ground of the duplex antenna can be reused as the reflector for FPC. Even there three duplex sources on the ground, it will not affect the reflectivity of the wave in FPC due to the relatively small radiation aperture of the slot. By utilizing this method, the experimental results show that the realized gains of two channels are increased to 15.2 and 16.2 dBi, respectively, which are improved by more than 12 dB. Finally, three duplex slot antennas are placed on the bottom of the FPC, and excited individually. For two channels, the H-plane directive beams can be switched at −18°, 0°, and 18° relative to its broadside direction. The proposed antenna is a good candidate for vehicular communications systems such as vehicle-satellite and low-altitude communication where requires low profile, wide coverage range and long-distance data transmission.