Aperture-Shared Dual-Band High-Gain Beam-Scanning Antenna Hybridizing Reflection-Mode Fabry–Perot Cavity and Wide-Angle Reflectarray

Different from the aperture-shared antennas based on the transmission-mode (T-mode) Fabry–Perot-cavity-antenna (FPCA), the reflection-mode (R-mode) beam-scanning FPCA is first excavated to realize aperture multiplexing for realizing high-gain beam scanning in both operating bands. A high-band R-mode FPCA is chosen as the basic antenna, and a low-band wide-angle reflectarray (RA) is integrated into its partially reflective surface (PRS). A dual-band dual-function composite-structural PRS unit cell offering bidirectional energy asymmetric transmission in the high band and providing well-optimized phase distribution in the low band is proposed. The phase profile of the wide-angle RA is optimized by the virtual-diffraction-aperture approach using the genetic algorithm. The antenna prototype is designed, fabricated, and measured, realizing a −3 dB gain bandwidth of 12.7% (3.46–3.93 GHz) and 11.9% (6.60–7.44 GHz). The realized maximum gain in the low band and the high band are 16.1 dBi and 18.6 dBi, with an aperture efficiency of 32.3% and 16.5%, respectively. A ±36° and ±34° beam scanning range are also achieved for the low band and the high band with the scanning gain loss of 3.0 dB.