High Temperature Superconductor Film Microwave Surface Resistance Test

As the manufacture technology of High Temperature Superconductor (HTS) film is improved continually, it is applied more and more widely. Then it is becoming urgent to measure the microwave surface resistance of HTS film that is one of the most important parameters of HTS film.Two kinds of microwave surface resistance Rs measurements of high Tc superconductive thin films are introduced in this paper, two-resonator method and the sapphire resonator method. Though the structures of them are different, the basic theory is the same. By measuring the value of the resonator's quality factor and other relevant parameters, the microwave surface resistance Rs of testing sample can be determined.Two-resonator method is using to build the draft of International Measurement Standard of Rs for High Tc Superconductive Thin Films, in which the Rs value of the HTS films can be determined by unloaded Q's measured from two resonators by using simple formulas. There is integrated theoretic calculation, simple field, eliminate the reference of tanδto Rs, but the result comes from two samples without the conclusion of the conductor loss of cylindrical cavity.The sapphire resonator method studied in this paper is used to apply for the National Measurement Standard of Rs for High Tc Superconductive Thin Films, in which the Rs value of HTS film can be determined by measuring the change of the unloaded quality factors of the loaded resonator. In this method, the result comes from single sample with the radiate loss of cylindrical cavity concluded. Though both of the methods have it's own advantage and disadvantage, the Rs can be measured with high sensitivity.Based on enough thinking of the symmetry calibration, a series of improvements have been done for the sapphire resonator method which is applying for national Rs measurement. The automatic test system is also founded. The system features high sensitivity and good repeatability and can be successful used to measure HTS film with non-destructivity. And based on the international measurement, a two-resonator method resonator working at 12GHz is designed and fabricated. The coupling of the resonating...