One sampling-point diagnosis of faulty elements in phased array with random feeding phases

The Random Feeding Phases (RFP) method is proposed and validated for diagnosing faulty elements in phased arrays. The core principle involves applying random phases, obeying a uniform distribution, to each array element through phase shifters, thus inducing the statistical behavior of radiated field. For a normal and fault-free phased array with RFPs, statistical radiation patterns of the complex electric field (both the real and imaginary parts) at a fixed field point vary within a specific region, whose analytical deductions are performed and verified. When an element malfunctions, the corresponding source in the composite field disappears, disrupting the initial coherent superposition and altering the statistical boundaries of the radiation pattern. The sequential behavior associated with successive failures of individual elements is detected at particular sampling points, and the optimal sampling range is further precisely determined. By mapping the faulty cases to statistical patterns, fault diagnosis can be achieved through the measured distribution area of the statistical radiation pattern at a fixed location. Explicit physical interpretability is reflected. The number of sampling points as well as the testing costs are greatly reduced. Both simulated and experimental results demonstrate the efficacy of this method for phased arrays with one or two defective elements.