A Dual-band Dual-circularly Polarized GPS Antenna with Excellent Radiation Pattern

In this paper, a compact dual-band dual-circularly Global Positioning System (GPS) antenna consisting of multilayer microstrip patches with 4 arms and 4 feeding probes is presented. In order to simultaneously generate LHCP and RHCP, two input ports with a phase shift of 90° are employed for the feeding probes. Optimized by using a specially designed feeding cable, the radiation pattern shows that the proposed antenna possesses an excellent quality circularly polarized (CP) radiation pattern covering 1510–1580 MHz and 1660–1680 MHz bands with an axial ratio less than 8 dB. The proposed antenna has a wide angle CP radiation of 120° with low profile and a miniaturized structure of 0.194λ
0
×0.194λ
0
×0.130λ
0
at 1.575 GHz, which makes it be of excellent practicability for GPS applications.