X-Band Mixing Performance of Y1Ba2Cu3O7-x Step-Edge Junction

Abstract
The X-band mixing performance of some step-edge junctions using Y1Ba2Cu3O7- x films has been evaluated. The mixing conversion efficiency (η) depends predominantly on normal resistance (R n) of a junction, which determines impedance matching for the microstrip signal line. Under constant impedance conditions obtained from temperature dependence of R n, conversion efficiency (η) increases with increase of the I c R n product. In the range of 12 GHz, however, the efficiency is saturated above the I c R n product of 1 mV. This tendency agrees with our simulation based on the resistively shunted junction (RSJ) model.