High resolution permittivity reconstruction of one dimensional stratified dielectric media from broadband measurement data in the W-band

For many security or Non Destructive Testing (NDT) applications it is desirable to detect and reconstruct dielectric stratified media to classify the investigated device under test (DUT). With rotational invariance techniques like the matrix pencil method (MPM) it is possible to improve the parameter estimation of a harmonic signal in contrast to the classical FFT based methods. By applying a time gating procedure prior to the MPM it is possible to reduce the influence of noise and multipath signals. Hence an improved parameter estimation is possible. Based on an optimized layer stripping algorithm it is possible to overestimate the number of layers in the stratified media and combine approximately similar layers.