A Regularized Source Current Reconstruction Method for Reactive Near Field to Far Field Transformation

摘要

The source current reconstruction method (SRM) is based on reconstructing equivalent current from the known electric field and can be used as a method of near field to far field transformation. In this paper for the first time the reactive near field (RNF) to far field (FF) transformation based on SRM is carefully studied. It is shown that in the RNF region, the singular values of the SRM transformation matrix can magnify the evanescent modes of RNF region and unstable the SRM iterative solvers. Therefore, in this paper for RNF/FF transformation a regularized SRM is proposed and the equivalent magnetic current of an antenna under test is reconstructed from the Tikhonov SRM equation. The regularization parameter of the Tikhonov equation is determined by the L-curve method. The effect of near field distance and noise on the accuracy of far field transformation of the proposed algorithm are studied in two different antenna simulations. It is shown that in all cases in the RNF region a regularized SRM have more stable behavior and more accurate results.