Compact circularly-polarized antenna with spiral slots for CNSS dual-band applications

A novel compact single-feed circularly-polarized (CP) antenna is proposed for CNSS dual-band applications. The antenna comprises a small circular patch with embedded four spiral square slots around the boundary and a narrow slot in the center. It is observed that the lower (1615MHz) and upper (2498MHz) resonance frequencies are controlled by the circular patch and the spiral slots. The CP operation is mainly achieved by the narrow slot. The antenna has a low profile and a small size with a radius of 19.7mm. Experimental and measured results show that the proposed antenna has good circular polarization characteristics.