Near-field scattering evaluation based on improved PO and EECs

An algorithm for the improvement of the physical optics (PO) and equivalent edge currents (EECs) integral calculating near-field scattering is presented in this work. The solution is obtained by a more accurate representation of the Green function with an expansion centre that lies in the neighbourhood of the sources of interest. Phase and amplitude improvements of the approximate Green function overcome the shortcomings of the conventional PO and EEC for scattering evaluation in near-field regions. The improved algorithm preserves the simplicity and computational efficiency of the classical one and applies directly to near-field scattering. Under the consideration of the antenna radiation pattern, the formula of near-field scattering is derived. The applicability and accuracy of the proposed algorithm is demonstrated by numerical simulations.