Tri-band circularly polarized stacked microstrip antenna for GPS and CNSS applications

A compact single-feed stacked microstrip patch antenna for tri-band circularly polarized (CP) application is presented. The proposed antenna with two properly square patches. By inserting two pairs of narrow slots parallel to the edges of the top square patch, with two protruding slots perpendicular to the edge, the top patch can perform CNSS dual-frequency (1.61 GHz and 2.49 GHz) CP radiations using a single probe feed. The GPS frequency (1.57 GHz) is achieved by cutting a slit in the bottom square patch and by adjusting the length of the slit, the antenna can perform CP radiation. Details of the proposed antenna design and results for the obtained tri-band CP performances are presented and discussed.