Terahertz Windmill-Shaped Circularly Polarized Pattern Reconfigurable Antenna with MEMS Switches

A circularly polarized pattern reconfigurable patch antenna operating in the terahertz band is presented in this paper. The geometry of this antenna can be changed by controlling the on and off state of four MEMS switches. By connecting one of parasitic arms and coupling with the others, the patch antenna at each state will radiate unique circularly polarized tilted beam. The proposed series MEMS switch has high isolation in terahertz band. The mechanical optimization is applied on the switch to achieve a low pull-down voltage while maintaining low profile. Besides, a four-port feeding network is designed to eliminate differences in different states. The simulated results show that the proposed antenna achieves a stable pattern bandwidth from 340 GHz to 350 GHz with reflection coefficient S11<-15 dB.