Small Single Band Circular Polarization and Dual Band Circular Patch Antenna

This paper presents a design for circular patch antenna with single feed for circular polarization. As an example, patch antenna is designed to operate CP in the ISM band (2.4-2.483 GHz) for WLAN and satellite communication application. CP of the proposed structure can be achieved by embedding two circular slots in the patch resonator. By changing the size and position of the slots, two orthogonal modes with equal amplitude and 90deg out of phase are simultaneously excited. The proposed CP antennas are excited by only single feed without using 90deg phase shifter. By proper arrangement of two circular slots, dual band antenna for WLAN and DMB application can also be successfully excited