Fast Antenna Array Diagnosis Based on Shifted Base Mode Character From Sparse Measurements

A novel fast antenna array diagnosis based on the shifted base mode character is presented. The problem is solved by the following steps: first, mathematically shift the reference phase origin (RPO) of the damaged far-field (FF) to the position of each element of the array one by one, then represent the shifted FFs with orthogonal mode, and then extract the base mode. In this way, the mapping from the element positions to the shifted base modes is established. Because the base mode is a sinc function of the off-center distance, the base mode shifted to the position of the faulty element will change significantly compared with the one shifted to its adjacent element. Since the larger sampling interval will not cause the base modes aliasing, the method can fast locate the faulty elements from sparse sampling (close to but less than twice the Nyquist interval). Compared with the existing methods based on compressive sensing and genetic algorithms, the proposed method avoids the prior knowledge of the failure-free array radiation pattern and the iteration solution, which can remarkably reduce the time of the measurement and data postprocessing. A wide set of full-wave simulations is done to assess the efficiency of the method.