Electromagnetic Characterization of Materials Based on Genetic Algorithm and Prior Knowledge

This paper proposes a method for extracting the complex permittivity of materials, utilizing genetic algorithm optimization and prior knowledge. S-parameters of the grounded coplanar waveguide with an upper cover containing the material under test are obtained through simulation in CST. Then, the genetic algorithm optimization procedure of a finite element method (FEM) software is utilized to minimize the difference between the simulated S-parameters from CST and FEM. Finally, the possible optimal values of the permittivity are searched iteratively. The approach can be used to extract material parameters across a wide frequency spectrum. To validate the proposed method, experiments were conducted using pure water as the test material.