A Novel Multimode Reduced-Surface-Wave Antenna for GNSS Applications

A novel multimode reduced-surface-wave antenna is proposed for Global Navigation Satellite System (GNSS) applications. Based on the shorted-annular-ring reduced-surface-wave (SAR-RSW) element and the inverted-shorted-annular-ring reduced-surface-wave (ISAR-RSW) element, proximity-coupled probe feeds are adopted to increase impedance bandwidth, and the defected ground structure band-rejection filters are inserted to suppress the mutual coupling between the SAR-RSW and ISAR-RSW elements. Experiment results indicate that the antenna has a less than 10-dB return-loss bandwidth in the range of 1.164-1.255 and 1.552-1.610 GHz, a 3-dB axial-ratio bandwidth from 1.16 to 1.26 GHz and from 1.54 to 1.61 GHz, and a larger than 7-dBi gain in the whole operating band.