Millimeter-Wave Cavity-Backed Multi-Linear Polarization Reconfigurable Antenna
Shu‐Lin Chen, Yanhui Liu, He Zhu, Dingzhao Chen, Y. Jay Guo
Abstract
Polarization reconfigurable antennas at millimeter-wave (mm-wave) frequencies are important technologies for 5G and beyond wireless communications systems. This paper presents a mm-wave multi-linear polarization (LP) reconfigurable antenna. It employs a resonant TM510-mode air-filled cavity as the base, and a circular array of slots is uniformly etched on its top surface to provide a rotationally-symmetrical “excitation” for the multi-LP antenna. An upper substrate printed with engineered patch layers is introduced above the slots for an in-phase high-gain composition, and it is mechanically rotated to facilitate the multi-LP reconfiguration. Each slot radiation is separately monitored and analyzed by using single-slot cavity models. A final multi-LP antenna that can switch among five LP states at mm-wave band was constructed. To overcome the classic high sidelobe problem associated with circular arrays, a modified bottom layer is introduced to the multi-LP antenna. The measured overlapped bandwidth of the optimized multi-LP antenna ranges from 28.58 to 28.99 GHz. For all of the five LP states, the simulated and measured sidelobe levels are –13 and –10 dB, respectively. The measured realized gains are varied from 15.5 to 16.8 dBi in the overlapped operating bandwidth. This is the first time to report a mm-wave multi-LP reconfigurable antenna.