Random symmetric phase feeding compensation method for phased array radar based on equivalent monopulse model

In a phased array radar, the phase quantisation error of phase shifters can lead to the beam steering error (BSE) between the predetermined and the actual directions. Existing researches on phase feeding optimisation suffer from high computational complexity and large storage space. In this study, an equivalent monopulse method is first proposed to yield the BSE with O(N) complexity by formulating the equation between the phase quantisation error and BSE. Further, a symmetric phase feeding compensation (SPFC) method is developed on the basis of the proposed scheme to cancel the phase quantisation error employing a symmetric planar array. Subsequently, a random phase compensation method is formulated to further reduce the residual quantisation errors of SPFC, and a random symmetric phase feeding compensation (RSPFC) method is proposed. The proposed SPFC and RSPFC methods possess O(N) complexities and allow for parallel calculation of element phase feedings, thus making the proposed methods more applicable on the embedded beam controller of a phased array radar. Based on computer simulations and phased array radar experiments, the proposed SPFC and RSPFC methods are validated to yield superior beam pointing accuracies and can improve the fluctuations in angle tracking.