Design of wideband CPW-Fed circularly polarized slot antenna

This paper presents a novel compact wideband CPW-fed circularly polarized (CP) printed slot antenna. The proposed antenna features an irregular slot and a tapered tuning stub protruded into the slot from the signal strip of the CPW. Wideband CP operation is achieved by changing the shapes of the slot. The simulated bandwidths of 3-dB axial ratio (AR) and 10-dB return loss are respectively around 91% (1.9 GHz-6 GHz) and 82% (2.7 GHz-6.4GHz) with the center frequency of 4.5GHz. The CP bandwidth of this antenna is 73% (from 2.7 GHz to 6 GHz). The measured gain is more than 3.8dBi over the CP bandwidth. Overall antenna size is 0.9λ×0.9λ with the thickness of 1mm, relative to the center frequency of 4.5 GHz.