WIDEBAND CPW-FED CIRCULARLY POLARIZED ANTENNA WITH MODIFIED FEEDING LINE AND SYMMETRIC ELLIPSE-APERTURE

This paper presents a new design for wide slot circularly polarized (CP) antenna (WSCPA). The proposed design possesses much larger return loss bandwidths and CP bandwidths than existing WSCPA. The main features of the antenna structure include a modified CPW feeding line and a wide and symmetric ellipse-aperture along the diagonal axis. By properly tuning axial ratio of ellipse-aperture and parameters of feeding line, wideband return loss and CP radiations can be achieved. The measured bandwidths of 10-dB return loss and 3-dB axial ratio (AR) are as large as 112.5% (2.1-7.5 GHz) and 109% (2.3-7.8 GHz), respectively. The improvement process of the AR and S11 properties is completely presented and discussed in this paper.