A Wide-Band Equivalent Source Reconstruction Method Exploiting the Stoer-Bulirsch Algorithm With the Adaptive Frequency Sampling

Conventional equivalent source reconstruction methods are only operating at a single frequency point each time. However, for wide-band radiators, their computation cost of the source reconstruction increases with the number of frequency points. In this communication, a wide-band equivalent source reconstruction method (WB-SRM) based on the Neville-type Stoer-Bulirsch (SB) algorithm is developed. Since the SB algorithm is a recursive tabular method, it can perform the interpolation over a broadband using a single rational function without any singularity issue. Supported by the adaptive frequency sampling (AFS) scheme, the number of required sampling data is significantly reduced, which leads to much better computational efficiency. During the AFS process, three fitting models (FM) are considered: two are "triangle rules," and another one is "rhombus rule." In this communication, a bisection searching strategy is performed. Furthermore, to achieve high-order accuracy, the Nystrom method is implemented. Numerical examples are presented to validate the proposed WB-SRM and demonstrate its accuracy and applications.