Fault diagnostics of realistic arrays from a reduced number of phaseless near field measurements

We present a new approach to the problem of detecting element failures in any kind of array antenna. The proposed method requires only phaseless information on the generated field and reduces as much as possible the number of needed measurements by exploiting the compressed sensing (CS) theory. The solution procedure works regardless of whether the probes are located in the near-field or in far-field region of the antenna under test, and it is the first and only CS-based technique able to perform the diagnostics by exploiting only phaseless measurements taken exclusively in the near-field zone. It is also simple and fast as it requires a single measurement surface and reduces, in most practical instances, to the solution of a convex programming problem. The given theory is supported by very many numerical experiments involving full-wave electromagnetic simulations of realistic arrays and considering both scalar and vector fields with different types of scanning surfaces and different noise levels. Both ON-OFF and phase faults are dealt with. An experimental validation of a fabricated array is also presented.