A Very Simple Dual-band Dual-sense Circularly Polarized Square Slot Antenna

A dual-wideband dual-sense circularly polarized (CP) square slot antenna is presented in this paper. The righthand circular polarization (RHCP) in +z direction for the lower frequency is mainly realized by an inverted L-shaped strip (ILSS). And the left-hand circular polarization (LHCP) in +z direction for the upper frequency is mainly achieved by an offset feed structure (OFS). The measured 10-dB return loss bandwidth is 114.7% (1.75-6.46 GHz). Its measured 3-dB axial-ratio (AR) bandwidths in the broadside direction are 60.2 % (1.8-3.35 GHz) in the lower band and 32.7% (4.6-6.41 GHz) in the upper band, which can fully cover all the WLAN and Wi-Fi bands.