Circular polarization-agile and beam switching enabled reconfigurable cavity-backed antenna

In this paper, a circular polarization-agile and beam switching enabled reconfigurable cavity-backed antenna having the ability to steer its radiation beam in different directions is presented. The antenna consists of two Eshaped driven patches, a tunable phase shifter integrated with PIN diodes for pattern switching and four switchable feeding probes for implementing polarization agility. The proposed antenna can simultaneously change its polarization and pattern. Beam switching and polarization agility are independently controlled by altering the OFF-ON states of diodes loaded on the feed network and switchable feeding probes. For validity of the proposed concept, the antenna prototype is fabricated and tested. The proposed antenna has measured impedance bandwidth (S11 < -10 dB) and 3 dB axial ratio bandwidths of 23% and 17.4% respectively for all states over the frequency range 4.7-5.6 GHz. The measured and simulation results show that the antenna can scan up to 30 degrees with five reconfigurable beams and two polarizations states for each reconfigurable beam.