Fast algorithm for electromagnetic scattering by buried conducting plates of large size

This letter presents a fast algorithm for electromagnetic scattering by buried conducting plates of large size and arbitrary shape using the conjugate gradient (CG) method combined with the fast Fourier transform (FFT). Due to the use of FFT in handling the cyclic convolutions related to Toeplitz matrices, the Sommerfeld integrals' evaluation for the buried scattering problem, which is usually time consuming, has been reduced to a minimum. The memory required for this algorithm is of the order N-the number of unknowns-and the computational complexity is of order N/sub iter/NlogN (N/sub iter/ is the iteration number N/sub iter//spl Lt/N for large problems).