Toward High-Performance Wideband GNSS Antennas-Design Tradeoffs and Development of Wideband Feed Network Structure

Many Global Positioning System (GPS) services have been recently introduced that extend over a wide frequency range from 1.16 to 1.61 GHz. For reception, either a wideband or multiband receiver is required, which is typically challenging to design as it requires a wideband feed network and a wideband circularly polarized antenna. Here, we investigate a high-performance Global Navigation Satellite Systems (GNSS) patch antenna fed by a wideband feed network to provide circular polarization (CP) over the whole bandwidth. The feed of the developed CP patch antenna requires 0°, 90°, 180°, and 270° sequential phase shift; an improved feed network with ±8° phase imbalance is designed to be used in the circularly polarized antenna. The manufactured antenna demonstrated a return loss better than 10 dB, axial ratio <; 1.7 dB, and RHCP gain >4.8 dB over the entire GNSS band. The developed antenna was connected to a GNSS receiver which tracked up to 28 satellites and the C/N0 of the received GNSS signals was better than 50 dB. Such a high-performance antenna design targets precise localization market.