DC-BIASED COPLANAR WAVEGUIDE ON THE BASIS OF HIGH-TC SUPERCONDUCTING THIN FILM WITH NONLINEAR IMPEDANCE

Abstract

Nonlinear properties of coplanar waveguide developed on the base of high temperature superconductor (HTS) YBa2Cu3O7−δ epitaxial thin film sputtered on single crystal Al2O3 substrate are investigated in X-band and temperature interval from 77K to 90K. It is shown that application of dc-bias to the structure allows controlling the microwave nonlinearity of HTS transmission line. The observed periodic features in losses as a function of temperature indicate that a phase coefficient of propagation constant has nonlinear behaviour related to the properties of transmission line. The phenomenological characteristic value of the input power P0 is determined from comparison experimental data with results of theoretical analysis.