Abstract:
In this paper, a circularly polarized analog phased array is proposed with wide axial ratio bandwidth. The circularly polarized analog phased array is composed of a sequential rotation antenna array, a phased array radio frequency circuit, and a phased array digital control circuit, forming a complete phased array system. Firstly, to optimize the axial ratio, the sequential rotation feed network is introduced into the circularly polarized analog phased array and a 90°~180° combination sequential rotation feed network is proposed. The sequential rotation feed network enables the phased array to achieve low axial ratio over a wide bandwidth range. Furthermore, a phased array digital control circuit is designed, with a low-complexity phase control utilizing integrated capacitor chip selection scheme. Finally, to validate the performance, simulations are conducted on the phased array. The simulation results show that the circularly polarized analog phased array achieves a -10 dB impedance bandwidth ranging from 2.15 GHz~2.81 GHz and a scanning range of ±50°. The axial ratio bandwidth of the normal beam covers from 2.00 GHz~3.00 GHz.