Toward High-Performance Wideband GNSS Antennas-Design Tradeoffs and Development of Wideband Feed Network Structure
Farshid Tamjid, Farnaz Foroughian, Chris M. Thomas, Ahmadreza Ghahreamani, Robab Kazemi, Aly E. Fathy
Abstract
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.