Three-dimensional microwave resonator tomography using spectral expansion of the object function

A novel method for imaging 3D permittivity distributions is presented. It allows the quantitative reconstruction of the real and imaginary parts of the permittivity and is applicable to strong scatterers and media with losses as high as in most biological tissues. The method is based on the spectral expansion of the permittivity function in the material under test in conjunction with an iterative solution of the direct problem using an FDTD solver. Availability is demonstrated on imaging examples. The new imaging method gives excellent results in all considered cases.