Compact Dual-Band Dual-Polarized Antenna Array for Robust Satellite Navigation Receivers

Multi-antenna satellite navigation receivers provide precision and robustness against multipath propagation and in-band interferers. However, with the prerequisite of compactness, the radiation efficiency of the array is limited by the strong mutual coupling between its elements. Decoupling and matching networks are used to mitigate the coupling and thus enhance the higher-order eigenmode radiation efficiencies of the array. Nevertheless, this limitation of efficiency motivates to exploit further sources of diversity and therefore dual-band dual-polarized compact antenna arrays with corresponding decoupling and matching networks are proposed. The compactness and integration of the receiver are improved by designing the networks on a multi-layer printed circuit board attached directly to the antenna. The decoupling elements are designed in stripline technology and the matching networks are based on lumped-element circuits. Measurement results show acceptable decoupling between the eigenmodes of the array and enhanced eigen-efficiencies. On the other hand, the measured purity of eigenmode excitation reveals room for improvement both at radiating element level and excitation network level.