Study On Measurement Of The Surface Impedance Of High Temperature Superconducting Thin Films With Parallel Plate

High-temperature superconductivity technology is widely used today because of its superiority.Especially with the continuous improvement of high-temperature superconducting thin film technology,it has an optimistic prospect of being widely used in the electronic information field.High-temperature superconducting thin films' microwave surface impedance is an important parameter in judging quality of the film.Therefore,the method to measure high-temperature superconductor thin films' microwave surface impedance plays an important role.At present,such researches in this respect are carried on in many countries over the world.This paper particularly presents the principle of measuring high-temperature superconductor thin films' microwave surface impedance with Parallel Plate Resonators,builds the model of the tested cavity,simulates and analyzes this model. The situation of the cavum and the added cavity of the Parallel Plate Resonator are both simulated and analyzed in the experiment,and then S₂₁ coefficient graphs are compared and optimized.Then the ideal thickness of septa and the optimum inserted depth of the probe have been got,and according to this result the tested cavity is designed.Finally,the testing cavity has been produced and the testing result in practice matches the simulation result.Since the project was established,this method has been continuously experimented through simulation for many times,solving the difficulty problem of coupling,successfully making the parallel plate resonator produce a resonant effect, lowing the resonant frequency of the Parallel Plate Resonators to 4.7 GHz,and achieving the goal of measuring high temperature superconducting thin films on microwave vector network analyzer with low frequency.