A Method for Measuring Dielectric Properties of Dielectric Laminates

In order to determine the unknown complex permittivity of any microwave dielectric laminate, this paper describes a reliable and accurate method for obtaining the complex permittivity. The coaxial probe method is used as the first step to predict the complex permittivity of unknown dielectric laminates. The second step is a regulating step, wherein microstrip-line (ML) open-circuit stubs (OCSs) are designed and fabricated based on the complex permittivity obtained from the first step. These values are used as the reference values to establish an electromagnetic model using EM simulator CST, and compared with the measured mean value of input impedance of OCSs. The complex permittivity of microwave dielectric laminates is then derived by matching the input impedance of the electromagnetic model with the actual one.