A Dual-Band Circularly-Polarized Antenna with Double C Shape Strips

Abstract

A new design of dual-band circular polarized antenna is presented. The proposed antenna is achieved using microstrip-fed with two circular strips and two circular patch. One circular strip radiates lower band, the other one covers higher band. By adding the circular patch on the back of the substrate, the left-hand circular polarization (LHCP) gain at the positive z axial of this proposed antenna has been improved. The antenna operates in two bands which are 2.5GHz and 5.2GHz. These two operating bands can be applied for the WiMax and WLAN application. Experimental results show the proposed antenna has good return loss and circular polarization characteristics. The 10 dB return loss impedance bandwidths for the lower band (2.5GHz) and higher band (5.2GHz) are 50% and 23%, respectively. The 3dB axial-ratio bandwidth are 14.8% and 4.0% with respect to 2.5GHz and 5.2GHz, respectively.