Efficient Wide-Band Evaluation of Electromagnetic Wave Scattering From Complex Targets

A skeleton-based wide-band algorithm (SBWBA) is proposed to efficiently evaluate radar cross section (RCS) from complex targets over a wide frequency band. The algorithm begins with generating a matrix, ~I, from which skeleton frequencies (SFs) are extracted by the proposed skeleton frequency extraction (SFE) strategy. The SFE strategy employs an adaptive manner to select SFs through the interpolative decomposition (ID) skeletonization. After the RCS results associated with the SFs are obtained, the complete wide-band response can be recovered through the ID efficiently. An inherent requirement for the employment of ~I and the SFE strategy is that the equivalent currents vary smoothly and slowly with frequency, which is satisfied only when the frequency band is sufficiently narrow. A multiinterval SFE strategy is developed as a remedy by automatically dividing the wide frequency band into several relatively narrow ones. Numerical experiments on complex targets have been performed to show efficiency and accuracy of the proposed SBWBA.