A Simple Method of Dielectric Constant Measurement Using a Microstrip Resonator

The dielectric constant of a substrate is a fundamental parameter in circuit design. In general, the dielectric constant is frequency-dependent. Therefore, if the dielectric constant at the frequency used is unknown, the designer will need to measure it. Measuring the frequency response of a microstrip line pattern on a planar substrate and comparing it to simulation results is one simple and effective solution. However, as far as we know, the dielectric constant entered into the simulator needed to be adjusted by experience. In this study, we derived an expression to determine the dielectric constant to input next into the simulator. We confirmed that the value derived using this expression rapidly converges through experiments. Using this expression reduces the number of times you have to input values into the simulator and run simulations, which is a very bothersome task. It is also expected to contribute to the automation of dielectric constant measurement.