Design of Dual-band Coaxial Aperture-shared High-precision GNSS Antenna with Wide Beamwidth

keywords:circularly polarized antenna  miniaturization  aperture-shared  wide beamwidth  parasitic branch

Abstract:In order to broaden the beam width of the circularly polarized antenna for high-precision satellite navigation and positioning and realize the miniaturization design of the antenna, a miniaturized dual-band aperture-shared microstrip patch antenna with light weight and wide beam width is presented. The antenna consists of an inner-outer cross-nested dual-band coaxial apertureshared radiation patch unit, several parasitic branches, several metal supporting columns, four feeding probes and a ground plane. The higher-frequency and the lower-frequency radiation patches are printed on the upper and lower surfaces of the PCB board, respectively, and the air is used as the common radiation dielectric layer, so as to realize the lower profile design of the antenna. In addition, the higher-frequency and the lower-frequency radiation patches are cross-designed locally in vertical direction, and several T-shaped parasitic short-circuit stubs are designed on the periphery of the annular lower-frequency radiation patch, forming capacity-loaded, respectively, so as to realize the miniaturization of the antenna, and the dimensions of proposed antenna are only 0. 37λ×0. 37λ×0. 03λ. The measured datas show that the maximum gain of the proposed antenna in both bands are greater than 4. 5 dBi, the gains are greater than 1 dBi at low frequency of 1. 227 GHz and low elevation angle of 20°, the gains are greater than 0 dBi at high frequency of 1. 575 GHz and low elevation angle of 20°. Therefore, the antenna proposed in this paper can better meet the needs of high-precision satellite navigation and positioning terminals.