Modeling and experimental investigation of microstrip resonators and filters based on High-Temperature Superconductor films

Complex approach to the investigation of microstrip resonators and filters based on High-Temperature Superconductor (HTS) films is described, which includes modeling of the electrodynamic parameters of HTS films, designing of microstrip resonators and filters, their manufacturing, and testing. Test samples were prepared using YBCO films on 0.5-mm-thick lanthanum aluminate substrates. The resonators and filter structures were patterned using ion-beam photolithography. Experimental data were used to determine the parameters of the model of surface impedance of the YBCO film and the film thickness and permittivity. Adequacy of the model and reliability of the model parameters, which were used for the synthesis and design of a 4th-order filter, were confirmed by coincidence of the experimental and calculated characteristics.