A Compact High-Precision GNSS Antenna With a Miniaturized Choke Ring

This letter presents a miniaturized geodetic choke ring antenna for high-precision Global Navigation Satellite System applications. The antenna consists of crossed dipoles that are fed by two coaxial feedlines, a resonant ring over the dipoles, a cavity-backed reflector with a saw-tooth structure, and a miniaturized choke ring. The choke ring alongside the saw-tooth structure can improve the front-to-back ratio (FBR) by almost 10 dB. The proposed antenna achieves a gain of over 7 dBic, a high FBR of greater than 25 dB, and an operating band covering 1.17-1.60 GHz in which the return loss is lower than -10 dB and the axial ratio is lower than 3 dB when zenith angle θ <; 70°.