CPW-Fed Circular Polarized Square Slot Antenna for GPS Applications

This study presents a design of a circular polarized square slot antenna (CPSSA) with a coplanar waveguide (CPW) for global positioning system (GPS) applications. The proposed antenna is composed of rectangular metal frame acting as a ground, two metal defected square rings at the back of the antenna and feed strip of CPW with an L-shaped. The GPS frequency of 1.57 GHz can be obtained by setting the corresponding parameters. The designed antenna has a small size of 56 × 56 × 0.8 mm3. The simulated impedance bandwidth of the proposed antenna is 220 MHz from 1.54 to 1.76 GHz for VSWR less than 2, and the axial ratio (AR) bandwidth is 75 MHz less than 3 dB from 1.525 to 1.6 GHz, which appropriate the GPS L1 band requirement. Meanwhile, the radiation pattern is a bidirectional pattern with a maximum antenna gain of around -3.9 dB. The antenna can be used for GPS applications adopting circular polarization.