Dual-band and dual circularly polarized sequential rotation antenna array for vehicle satellite communications

Abstract

ABSTRACT A novel dual-band dual circularly polarized antenna array is proposed for vehicle satellite communication systems. The dual-band filtering element is presented, in which the dual-band characteristics are realized by vertically feeding method. The ring-shaped frequency selective configurations (RFSC) are added to the feeding network for the filtering function. The sequential rotation array is achieved by rotating four identical antenna elements around z-axis, where the phase difference of adjacent elements is 90° or −90° for the left-hand circular polarization and right-hand circular polarization, respectively. A decoupling approach is introduced to change the current paths on the surface of radiator with cutting orthogonal slots, which solves the problem of serious coupling between the different elements of the sequential rotation array. The prototype is fabricated and measured to verify the reliability of the simulations, and the simulations and measurements have reasonable consistency. The impedance bandwidths of the array are 7.26–7.46 GHz and 8.07–8.36 GHz, respectively. The port isolation of the array is greater than 30 dB in the two bands. The axial ratio (AR) bandwidths are 7.12–7.48 GHz and 8–8.36 GHz, respectively. The designed array has a promising application prospect for vehicles to satellite communications.