An Efficient Hybrid Method of CBFM/AIM and Equivalent Dipole Moment for Computation of Electromagnetic Scattering Problems

A new hybrid method CBFM/AIM-EDM is introduced to analyze the bistatic radar cross section (BCS) of perfect electrical conductor (PEC) scatterers. This method efficiently treats electromagnetic scattering problems from discrete objects using the electric field integral equation (EFIE). Initially, CBFM divides the target into multiple subdomains, with each subdomain is enclosed with its respective local Cartesian grid. Then, the macro basis functions within each subdomain are transformed into the local Cartesian grid. The AIM is utilized to accelerate the construction of CBFs, and the matrix vector multiplication process in the reduced matrix is carried out by the fast Fourier transform (FFT). In addition, the equivalent dipole moment (EDM) is introduced to speed up the calculation of the interaction between subdomains. Numerical results show that the proposed method successfully addresses the problem that conventional AIM is only suitable for computing targets with dense distributions of unknowns. This approach not only avoids the waste of numerous auxiliary grid points and lowers memory demands but also enhances computational efficiency and the convergence rate of the iterative process.