A microwave method for complex permittivity extraction of thin materials

an improved microwave method to extract the complex permittivity of solid and liquid materials filled in a short-circuited waveguide is developed. the method determines accurately the dielectric constant of thin and moderate thick samples. it eliminates the problems arising from any position offset of the dielectric slab in transmission / reflection methods. the proposed method is iterative and the initial value is calculated by using the 7th approximation order of trigonometric terms in the exact reflection coefficient equation. this approach is applied to the simulated data of low loss and dissipative materials in limited frequency band.