Electromagnetic imaging of permittivity profiles by an improved spectral inverse technique

A way to improve the ill-posedness of inverse scattering problems by making the cell size of the discretization much larger is proposed. In order to see the effect of the larger cell discretization, a 24-cell structure (0.1 lambda *0.1 lambda ) is divided into 4 large cells (0.1 lambda *0.6 lambda ). Step and continuous permittivity profiles are reconstructed by the 24-cell discretization and the 4-cell discretization, respectively, for X/sub 0/=0.3 lambda . The 4-cell discretization gives a result very close to the original dielectric profile, but the computation time is reduced significantly compared to the 24-cell inversion since the number of unknowns for 4-cell discretization is reduced to 12 from 24.<>