Equivalent current reconstruction technique for array and radar antenna diagnostic

The equivalent radiating current technique (EQC) is based on an integral equation formulation of the inverse source problem upon rigorous application of the equivalence principle. From the measured near or far field data it allows the accurate determination of the equivalent radiating sources on an arbitrary 3-D closed surface enclosing the Antenna Under Test (AUT). The main advantage of the integral equation formulation with respect to wave expansion techniques is its true geometry-independence both for the radiator in examination and the measurement range. The equivalent current technique is highly applicable in the testing, validation and diagnostics of antenna arrays and radars. Indeed, the visualization of the equivalent radiating currents on a surface conformal to the physical shape of the antenna is particularly useful to understand multi element array functioning and facilitate design improvements. This communication discuss different applications of the EQC technique in the testing of these antennas.