Analysis of Wide Band Scattering From Objects Using the Adaptive Improved Ultra-Wide Band Characteristic Basis Functions

Abstract

The improved ultra-wide band characteristic basis function method (IUCBFM) is an efficient approach to analyze the wide-band scattering problems because the improved ultra-wide characteristic basis functions (IUCBFs) can be reused for any frequency sample in the range of interest. However, the number of the IUCBFs constructed at the highest frequency point is excessive, and the computational complexity will be increased when applying the same number of IUCBFs at the lower frequency points. To mitigate this problem, an adaptive IUCBFs construction method is presented which can decrease the computational complexity at the lower frequency points. In the proposed method, the given frequency band is adaptively divided into multiple sub-bands in consideration of the number of the IUCBFs. The adaptive IUCBFs are obtained at the highest frequency point in each sub-band, which leads to smaller number of IUCBFs and significant reduction of solver time at lower frequency band. The numerical results have demonstrated the accuracy and efficiency of the proposed method.

Solution of Wideband Scattering Problems Using Hierarchical Ultra-Wideband Characteristic Basis Functions

“…The threshold of the SVD is set to 10 −3 . In order to decrease the computational complexity at the lower frequency points, the adaptive UCBFs construction method is used [21]. The equivalent dipolemoment method (EDM) [24] is applied to accelerate the impedance matrix element filling procedure.…”

“…This improvement is achieved by fully considering the mutual coupling effects among the sub-blocks to obtain the secondary level CBFs (SCBFs). In [21], an adaptive improved UCBFs (AIUCBFs) construction method is proposed, which can decrease the computational complexity at the lower frequency points. In [22], the unnecessary UCBFs are removed from the basis set as the frequency is decreased.…”

Efficient Computation of Wideband RCS Using Singular Value Decomposition Enhanced Improved Ultrawideband Characteristic Basis Function Method

“…In order to obtain enough CBFs for a given SVD threshold and for arbitrary geometries in the blocks, the redundant International Journal of Antennas and Propagation 3 PWs are usually chosen [11][12][13][14]. However, the redundancy of the PWs increases the solving time of the CBFs.…”

“…In [12], the construction of the UCBFs has been improved by fully considering the mutual coupling effects among the subblocks to obtain the secondary level CBFs (SCBFs), such that the improved UCBFs (IUCBFs) contain more current information and improve the calculation accuracy at lower frequency points. In [13], an adaptive IUCBFs construction method has been proposed and the adaptive IUCBFs have been obtained at the highest frequency point in each subband which leads to a smaller number of IUCBFs and significant reduction of solver time at lower frequency band. In [14], the unnecessary UCBFs have been removed from the basis set as the frequency is decreased.…”

“…In [14], the unnecessary UCBFs have been removed from the basis set as the frequency is decreased. However, in the generation step of the IUCBFs in [12][13][14], the choice of the number of incident plane waves (PWs) is typically made empirically and the redundant PWs are usually chosen which increases the solving time of the CBFs. To mitigate this problem, singular value decomposition (SVD) is adapted to enhance the efficiency of the CBFs generation in this paper.…”