Microwave imaging of multilayer cylinders using optimization techniques

The authors present a novel approach to solving the problem of the reconstruction of arbitrary strong-scattering objects using optimization techniques. The algorithm is based on the minimization of the mean-squared error between the measured and calculated scattered fields from the reconstruction. The object is assumed to have cylindrical symmetry, and the radial profile of permittivity is to be determined. The validity of the proposed algorithm is investigated both numerically and experimentally. In the experimental part, a tomographic microwave system operating at 2.45 GHz was used to measure the scattered field produced by a dielectric cylinder. A comparison between the measured scattered field and the theoretical field corresponding to the optimized cylinder epsilon =61.62 tan delta =0.38 R=2.23 cm is shown, and the reconstruction error is negligible for the radius and below 10% for the dielectric constant and loss tangent.<>