Intermodulation Measurements in Superconducting Meander Lines

초록

The intermodulation measurements are used to study the nonlinear effects in high Tc microstrip meander lines at microwave frequencies. The superconducting YBaCuO thin films were grown by laser ablation on both sides of lanthanum alumite substrates and the microstrip pattern was defined using photolithography. The meander line is excited by two microwave signals from two sweep oscillators at both frequencies of 4.70052 GHz and 4.69952 GHz over a temperature range of 19 to 80 K. The measured harmonic signals, except input microwave signals, show a gradual decrease in amplitude and have finally disappeared as the critical temperature is reached. As for the dependence on the input power, the amplitude (A) of the first - mode harmonic signals at 19 K shows a linear dependence on the power (p), A = 1.12p - 75, in the range of 12.5 - 15.0 dBm.