Dielectric property characterisation of thin films based on iterative comparisons of full-wave simulations and measurements

Abstract

A new research on characterising the dielectric constant and loss tangent of thin-film material with a convenient technique based on simulation is proposed. The authors utilise a set of full-wave electromagnetic simulation data to retrieve the dielectric properties from the measured data. More specifically, a set of simulation data is collected from a commercial full-wave simulator (Ansys HFSS) by solving the electromagnetic model the same as the measurement set-up which employs a grounded coplanar waveguide with a thin film placed on the top surface. The measured transmission coefficients (S21) are iteratively compared with its simulation data to estimate the dielectric constant and loss tangent using an efficient comparison algorithm. For adaptive data acquisitions and comparisons, they have developed a MATLAB code using hfss-matlab-toolbox that makes the whole process quick and automatic. They have successfully retrieved the dielectric properties of four different sprayed thin films at 8, 10, and 12 GHz, and observed that the dielectric constant and loss tangent strongly depends on their compositions, thickness, and frequency.