Design improvements of electrically large antennas using the inverse source method

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 [1]-[7]. This method offers a greater generality and flexibility since it allows reconstructing sources on arbitrary 3-D surfaces enclosing the antenna under test (AUT). Indeed the equivalent source approach is a true 3D approach as opposed to traditional methods based on plane wave expansion using hemispherical field information. The equivalent current technique is highly applicable in the testing, validation and diagnostics of a wide variety of antennas. 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 paper illustrate, by measured examples, the advantages of new enhancements of the method, which allow the user to process antennas with larger dimensions without scarifying accuracy and maintaining the dual equation formulation.