A CG-FFT method with nonuniform sampling for Pocklington´s equation

The conjugate gradient method combined with the fast Fourier transform (CG-FFT) is a suitable approach for large scatterers and radiating systems. The uniform sampling scheme, widely used in current applications, requires memory storage and computational complexity which increase very rapidly with the desired accuracy. In this work, to circumvent this difficulty for the case of large structures with localized isolated discontinuities, where higher accuracy (resolution) is required only over some specific parts, a nonuniform sampling scheme is presented. Although the proposed approach is more general, its application to Pocklington´s equation is investigated here. The CG-FFT method for uniform sampling is applied to the radiation and scattering problem of a straight wire antenna, for a wide range of lengths.<>