A Compact Wideband Dual Circularly Polarized Microstrip Patch Antenna Array for X-band Satellite Communication Systems

This paper presents a broadband dual circularly polarized microstrip patch antenna for satellite communication systems. The antenna consists of two-layered square patches and a 3-dB coupler which inherently provides equal amplitude signals with 90° phase difference to the orthogonal microstrips of the square patches. Correspondingly, a dual circularly polarized antenna is constructed. Then, a 2×2 antenna array fed by two well designed four-way Wilkinson power dividers is proposed. The simulation results show that the antenna array has a fractional impedance bandwidth of 16% for |S11| < -10 dB. In its operating frequency band, the antenna has a stable gain of higher than 15 dBi, and an axis ratio (AR) of lower than 3 dB.