Reconfigurable Circularly Polarized End-fire Antenna Design Based on Butterfly Dipoles

In order to reduce the damage to carrier aerodynamics by the antenna and improve the performance of the antenna in a complex electromagnetic environment, this paper designs a circularly polarized reconfigurable end-fire antenna. The antenna is based on the Substrate Integrated Waveguide (SIW) horn antenna. The front end of the horn is loaded with a phase shifter and butterfly dipoles, and four MEMS switches are loaded between the upper and lower butterfly dipoles. The current flow path can be controlled by the on and off of the switch, so that the antenna radiates two circularly polarized waves respectively. The measured results show that by controlling the on-off combination of the switch, the designed antenna can radiate Left-Hand Circular Polarization (LHCP) or Right-Hand Circular Polarization (RHCP) electromagnetic waves in the 11.24 similar to 11.83 GHz frequency band along the end-fire direction. The measurement results are basically consistent with the simulation results, verifying the effectiveness of the design.