Dual-Band dual-sense circularly polarized slot antenna

Abstract

A novel design of dual-band and dual-sense circularly polarized slot antenna with asymmetric CPW feed and asymmetric U-shape signal line is presented. A rectangular patch above the signal line helps to get circular polarization in the lower band. Axial ratio bandwidth is significantly enhanced in the lower band by using a strip above the parasitic element. By adding a meandered grounded stub, circular polarization in the upper band is achieved. The antenna has been designed and simulated. It has good circular polarization characteristics. The measured 10dB return loss impedance bandwidths are 56% (1.95GHz-3.47GHz) for the lower band (LHCP) and 4.05% (4.11GHz-4.28GHz) for the upper band (RHCP) respectively. The measured 3dB axial ratio bandwidths are 22.46% and 2.13% with respect to 2.85GHz (LHCP) and 4.23GHz (RHCP) respectively.