The Effect of Mutual Coupling on the Performance of GNSS Antenna Arrays

Serious mutual coupling effect must be taken into account for the miniaturized adaptive anti-jamming antenna arrays in global navigation satellite system (GNSS) receivers. In this paper, the effect of mutual coupling on the performance of GNSS antenna arrays has been comprehensively discussed. The nulling performance of the GNSS antenna array in presence of mutual coupling is efficiently evaluated by the proposed embedded element pattern method, which is further verified by a simulated miniaturized four-element GNSS antenna array in nonadaptive mode. In the space-time adaptive processing (STAP) array, a generalized wideband signal model based on the dispersion phenomenon is introduced to study the effect of mutual coupling on the optimal STAP array response, signal-to-interference-plus-noise ratio (SINR) loss, and the minimum mean square error (MMSE) of the Wiener filter. Employing the STAP normalized least mean square (NLMS) algorithm, the simulation results show that the mutual coupling leads to a decrease in convergence rate, an increase in misadjustment, and a loss of SINR, whether or not the compensation is considered.