Dual-frequency antenna circularly polarized for GPS-SDARS operation

In this paper we propose a novel low cost and original circularly polarized monolayer radiating structure with opposite senses of polarization, covering the 1.576 GHz global positioning system (GPS) and the 2.338 GHz satellite digital audio radio system (SDARS) bands. This antenna is made up of a central square patch and a square ring around, both with truncated corners, placed of the center of a square ground plane of small dimensions. The two parts are linked together by mean of four connecting small microstrip lines. It is printed on duroid substrate. A single coaxial probe feed is connected at few millimeters from the center of the antenna to create the circular polarization (CP) in the two frequency bands.