Wavelet matrix transform approach for electromagnetic scattering from an array of metal strips

The wavelet matrix transform approach, in combination with the method of mo ments (MoM), is applied to solve the electromagnetic scattering problem of an array of metal strips. The problem is first discretized by the conventio nal MoM to obtain a dense impedance matrix, then the wavelet matrix transfo rm is applied to produce a sparse matrix. This approach avoids a great numb er of integral computations existing in the wavelet basis expansion method and provides fast approach to solution for the scattering problem. Daubechi es' wavelet is chosen as the mother wavelet to construct a sparse wavelet m atrix so that the matrix-matrix multiplications occurring in the transform cost only O(N-2) with N unknowns. Numerical tests show that the computation cost necessary for solving the resultant sparse matrix is only O(N log N). An appropriate choice of the number of vanishing moments of wavelets is su ggested from consideration of total computation cost and accuracy of soluti ons.