Design of a broadband and high stable phase center navigation antenna

A broadband and high stable phase center navigation antenna is presented, in which wide voltage standing wave ratio (VSWR) and axial ratio (AR) bandwidths are realized by adopting Archimedes spiral antenna structure. Both phase center stability and multipath-suppressing capability are improved by designing a proper three-dimension (3D) choke-ring surrounding the Archimedes antenna. Correspondingly, a simulation model of the proposed antenna is established with a kind of commercial electromagnetic simulation software and its parameters are optimized simultaneously. The simulation results demonstrate that at all the operation frequency points of the GPS, COMPASS, GLONASS, and Galileo satellite navigation systems the VSWR is less than 1.45, AR less than 3dB in the main beam of elevation from-60° to 60°, phase center stability from -2.5° to 2.5° in the same main beam, and the gains of the frequency points are more than 5dB, etc. In contrast to the pure Archimedes spiral antenna, the front/back gain ratio (FBR) (defined as the difference of the gain values at elevation 60° and elevation 120°) of the loaded 3D choke-ring Archimedes antenna is improved as 2-6 dB. The work shows that the proposed antenna has a distinct advantage.