Sparse Array Synthesis of Duplex Dual Circularly Polarized Horn

In this paper, a circularly polarized (CP) horn antenna is designed and a sparse array containing receiving antennas, transmitting antennas and duplex antennas is formed. The horn antenna generates left-hand and right-hand CP (LHCP and RHCP) by different excitation directions as the transmitting and receiving antenna respectively. Genetic algorithm (GA) is used to optimize the placement of sparse arrays and suppress side lobe. The directionality is improved compared to the array consisting of only duplex antennas, and the number of duplexers is reduced.