Beamforming in compact antenna arrays for robust satellite navigation

In this paper the robustness of a four-element compact navigation antenna array against continuous-wave interferers is investigated. The compact antenna array is integrated with an analog decoupling and matching network to mitigate the mutual coupling between the antenna elements and restore efficient diversity gain. It is observed that the network improves the equivalent carrier-to-interference-plus-noise ratio by at least 3 dB in most directions for a three-interferer scenario. For a single, there is little benefit of the decoupling and matching network. However, the function of the array is intimately related to the performance of the front-end. Due to the unequal saturation of the first-stage low-noise receivers, the network provides the opportunity to select at least one channel remaining operational in the linear regime. This feature yields additional robustness to such compact receivers for detection and tracking in the presence of one strong interferer.