Dual-band dual-sense circularly polarised square slot antenna with simple structure

Adual-band dual-sense circularly polarised (CP) square slot antenna is presented. The proposed antenna consists of aL-shape patch and two rectangular strips around two opposite corners on the lower ground.By adjusting the size of them, a broadband dual-band dual-sense CP antenna can be obtained. It can radiate right-hand circular polarisation at 3.0 GHz and left-hand circular polarisation at 5.5 GHz at ⁺z direction. The measured results of impedance bandwidths for S₁₁ < -10 dB are 38.8% (2.51- 3.72 GHz) and 27.5% (4.83-6.37 GHz). The 3 dB axial ratio bandwidths are 37.4% (2.50-3.65 GHz) and 16.3% (5.02-5.91 GHz).