A Novel U-slot Aperture Coupled Annular-Ring Microstrip Patch Antenna for Multiband GNSS Applications

A multiband circularly polarized novel U-slot aperture coupled annular ring antenna is proposed in this paper. The antenna covers the bands of IRNSS - L1; GPS - L1, L2 and GLONASS - L1. The antenna has a stacked structure with two substrates separated by an air gap. The top substrate has two annular rings and the bottom substrate has the U-slots and the power divider network. The transmission and radiation characteristics were simulated and measured for the above mentioned bands. Measured S 11 is less than -10dB and axial ratio is better than 2.2dB over the proposed bands.