Filtering effects on permittivity profiles reconstructed by a spectral inverse scattering technique

A study is made of the reconstruction of permittivity profiles using the spectral inverse scattering scheme with the moment-method procedures. Based on earlier works, the reconstructed profiles have been affected by large errors even with a negligible random noise of the measured field. One of the intuitive approaches to reduce these errors has been implemented successfully by employing a polynomial basis function to the induced field on each enlarged cell in conjunction with a suitable weighting function. Another method is presented which adopts a low-pass filter to the spatial-Fourier transform of the equivalent source distribution induced in a dielectric object. The accuracy and validity of the spectral filtering are assured by a number of numerical simulations for a simple test geometry