A CORNER-FED SQUARE RING ANTENNA WITH AN L-SHAPED SLOT ON GROUND PLANE FOR GPS APPLICATION

This paper proposes a square ring patch antenna for GPS L1 band application. The square ring patch located on the center of an FR4 substrate was truncated a square to guide two resonant modes. The dimensions of the truncated square located on the center of the patch controls the antenna's frequency band. Larger truncated square creates longer resonant path that decreases the resonant band. To achieve the CP radiation patterns, the corner-fed method and a truncated L-shaped slot on the ground plane are applied. After the size of the truncated L-shaped slot is optimized, the currents of Eµ and E' are around 90 - shifts that make the antenna's AR lower than 3dB. By switching the positions of the feed point and the L-shaped slot, both RHCP and LHCP can be obtained individually. Beside the CP operation, the proposed design also has advantages of planar structure, simple design, low cost, and good performances.