A Small-Size, High-Gain, RadiationPattern-Reconfigurable Fabry-Pérot CavityAntenna for 5G Communication

This letter presents a small-size, high-gain radiation pattern-reconfigurable Fabry-P & eacute;rot cavity antenna (FPCA) operating in the N79 band. The proposed FPCA is a closed cavity consisting of a partially reflective surface (PRS) with a positive phase gradient, three feeding sources, four metallic sidewalls, and a simple feeding network with a SP4T switch. The PRS allows a high-gain operation in a wide bandwidth. The cavity is enclosed by metallic sidewalls to improve aperture efficiency. An SP4T switch is incorporated into the feeding structure to selectively excite different sources, and three beams (three states) are achieved. The measured results show that the overlapped -10 dB bandwidth of 150 MHz (4.87-5.02 GHz) is achieved at three states. At the three states, the measured beam of the FPCA can be steered in the 0 degrees, 17 degrees, and 343 degrees directions with peak gains of 11.4, 11.1, and 10.9 dBi, respectively.