RWG MoM‐via‐locally corrected Nyström method in near‐field to far‐field transformation using very‐near‐field measurement

Abstract

Locally corrected Nystrom (LCN) method is used to solve electric field integral equations (EFIE) of the equivalent current method in the planar very-near-field measurement of antennas and RF circuits. The exact relationship between the Rao–Wilton–Glisson (RWG) method of moments and first-order and zero-order LCN is established for both magnetic and electric currents to ensure normal current continuity between adjacent triangular patches. The proposed method is a point-based RWG discretisation of EFIE and causes a noticeable decrease in the degree of freedom. It consequently eliminates spurious charges and significantly lowers the condition number of the impedance matrix. Moreover, it is more efficient to be accelerated by fast algorithms such as multi-level fast multipole method. In what follows, the detailed explanation of the proposed method, along with the examples of current reconstruction and antenna far-field calculation, is presented.