Correlation of power handling capability and intermodulation distortion inYBa2Cu3O7-delta thin films

The nonlinearity of the microwave properties of coplanar thin-film YBa2Cu3O 7-delta resonators are examined by measurements of the degradation of the q uality factor Q(L) and the increase of the two-tone third-order intermodula tion distortion signal with increasing microwave power. A linear correlatio n between the data of the characteristic microwave powers, which are obtain ed for the degradation of Q(L) and the intermodulation signal, is experimen tally observed and explained in terms of a theoretical model based solely o n well-known expressions for the nonlinear surface resistance. Due to these experimental observations and the theoretical model, we conclude, that the degradation of the resonator Q factor and the generation of intermodulatio n distortion are determined by the same physical mechanism and that thermal effects can most likely be excluded. (C) 2001 American Institute of Physic s.