Integrated circular polarized microstrip antenna with dual‐mode‐polarization insensitive characteristics

Abstract

A dual-mode circularly polarized compact antenna with integrated left-hand and right-hand circular polarization (LHCP and RHCP) is presented in this work. A multilayer arrangement of a square patch and square ring structure with an irregular transmission line is analyzed for dual-band, dual-CP operation. To realize dual mode propagation the proposed structure is excited using electromagnetic coupling technique. Succeeding proximity feeding with T-stub match is analyzed, which conveys impedance bandwidth of 180 and 300 MHz within |S11| < −10 dB at 3.5 and 5.5 GHz. The designed CP elements is suitably arranged with feed line for generating two orthogonal polarization of equal amplitude and a 90° phase difference at both the resonant modes (TM10 and TM01). Alterable LHCP and RHCP performance is realized by altering the compensated position and peculiar angle. Having both LHCP and RHCP polarization this design shows polarization insensitive characteristic. Each LHCP and RHCP antenna element accomplished a 3-dB AR of 70 and 120 MHz with a gain up to 6 dBi. With a low profile of 0.27λ0 × 0.27λ0 × 0.04λ0, the CP antenna is fabricated, and the performance is validated through experimental analysis. With all the viable characteristics, the antenna is proposed for Wi-MAX/WLAN communication.