Wideband Sherman–Morrison–Woodbury Formula-Based Algorithm for Electromagnetic Scattering Problems

In this communication, a wideband Sherman–Morrison–Woodbury formula-based algorithm (WSMWA) is proposed to efficiently compute the wideband and wide-angle electromagnetic scattering problems. In the proposed algorithm, the standard adaptive cross approximation (ACA) decomposition is only performed at the highest frequency of the frequency band of interest to find the dominant basis functions for each far-block pair. Then, at any frequency within the entire frequency band, the approximate compression of the impedance matrix can be efficiently constructed by using the impedance interpolation method with the dominant basis functions selected at the highest frequency. As a result, the WSMWA avoids performing the standard ACA repeatedly and saves a lot of computational time in comparison with the conventional Sherman–Morrison–Woodbury formula-based algorithm (SMWA) for wideband and wide-angle applications. Numerical results for electromagnetic scattering are given to demonstrate the efficiency and accuracy of the proposed algorithm.