A W-band Wideband Circularly Polarized Reconfigurable Microstrip Antenna

In this paper, a wide band circularly polarized reconfigurable microstrip antenna is designed by using multivariate method. The antenna works in the W band, four radiation patches are fed coupling through the H-type gap, so that the adjacent patch radiation unit generates a pair of electromagnetic waves with vertical polarization. The 90° bridge is used to make each pair of electromagnetic waves with the same amplitude and 90°phase difference, so as to realize the circular polarization of the antenna. MEMS switch can be connected externally. Selecting the input end of a 90° bridge makes the phase between radiation elements advance or lag 90°, thus achieving reconfigurable left-right circular polarization. Ansoft HFSS simulation shows that the antenna has a central frequency point of 78 GHz, a return loss of less than -10 dB, a bandwidth of 13.9 GHz with a voltage standing wave ratio of less than 2, and a bandwidth of 15 GHz with an axial ratio of less than 3 dB, realizing the circular polarization performance of the antenna.