A Circularly Polarized Switched-Beam Antenna Array

This letter introduces a novel, inexpensive, and low-insertion-loss switch feeding network for beam steering of antenna array. The proposed network uses only a single-pole multithrow (SPMT) microwave p-i-n switch to steer the main beam to different angles with high gains. In theory, arbitrary angles and an arbitrary number of steering beams can be realized with this structure. This type of switch feeding network is used to successfully design a 2×3 circular polarization microstrip antenna array, and the experimental results are presented and discussed. Good agreements between simulation and testing are achieved.