A Fabry–Pérot Cavity Antenna with Wide and Narrow Beam Integration for Vehicle Mounted Hybrid Communication

To promote the integrated development of intelligent transportation systems (ITS), it is required that current and future vehicle mounted wireless devices can deploy unmanned aerial vehicles (UAV), and have communication capabilities with low altitude aircraft. This paper proposes a Fabry–Pérot cavity (FPC) antenna for vehicle mounted hybrid communication. It is the first attempt to apply outward-stepping reflector (OSR) to manipulate the reflection phase in FPC, contributing to expand beamwidth for horizontal polarized (H-pol) wave. In addition, a dual-functional metasurface (DFMS) is proposed. It functions as a partially reflective surface (PRS) for H-pol wave to achieve flat-top beam. Meanwhile, the DFMS also provides phase gradient switching in vertical polarized (V-pol) wave to form a high-gain pencil beam. For validation, a prototype of the vehicle mounted FPC antenna using above mentioned principle is designed, fabricated and measured. The proposed antenna yields a flat-top beam with 1.5 dB beamwidth of 85 deg and gain of 8.92 dBi in H-pol, and a high gain pencil beam with 3-dB beamwidth of 15 deg and peak gain of 16.84 dBi. This functionally-integrated concept enables the vehicular-platform to achieve wide coverage range and long distance sensing capability. It is a good candidate for hybrid communication scenarios such as the UAV network and V2V communications. © 2026 IEEE.