2022 Volume 19 Issue 6 Pages 20220012
A novel dual-band circularly-polarized frequency reconfigurable microstrip antenna with the feasibility of obtaining a relatively smaller size is proposed and demonstrated. Fed by a Wilkinson power divider with 90° phase difference, the proposed circularly-polarized frequency reconfigurable patch antenna, consisting of a patch radiator etched with a square-ring slot and a double-sided printed DC bias circuit, is designed, analyzed and fabricated. Good agreement between simulated and measured results is observed. Simulation and measurement results reveal that the proposed dual-band circularly polarized (CP) antenna for BeiDou navigation satellite system can provide impedance bandwidths of 4.1% (1.592-1.658GHz) and 5.5% (2.43-2.568GHz) for lower L band and upper S band respectively, as well as 3-dB axial ratio (AR) bandwidths of 1.5% (1.602-1.626GHz) and 1.7% (2.465-2.507GHz) for LHCP and RHCP respectively. Meanwhile, within the effective LHCP/RHCP bandwidths, the proposed antenna has gains from 3.6dBic to 4.2dBic with an average gain of 4.0dBic for LHCP, and gains from 3.3dBic to 3.6dBic with an average gain of 3.4dBic for RHCP, respectively.
