Dual band dual circularly polarized patch antenna for Ku-band applications

This paper proposes a duplex antenna, with four square patches to form a sequential rotating array, which can generate dual circular polarization radiation. A feeding network consisting of power dividers, phase shifters and couplers feeds the antenna with +/- 90 phase difference and achieves dual circular polarization. A band stop filter with low reflection is employed in the receive port to increase the isolation in the transmitting band (14-14.5 GHz) to over 30 dB. The receive port achieves a gain of over 4.8 dBi and an axial ratio under 3 dB in the receiving band (10.7-12.7 GHz). The transmit port has a gain of more than 5.1 dBi and a 3 dB axial ratio in the whole frequency band (10.5-15 GHz).