Parametric amplification by a Josephson junction line

In this paper, the parametric interaction of electromagnetic waves with the travelling vortex-array is studied in the case where a normal strip line is magnetically coupled with the Josephson junction line. The aim of the present analysis is to amplify the electromagnetic waves in a strip line by matching its propagation velocity with that of a travelling vortex-array in the Josephson junction line. Calculations are based on the small signal analysis taking an exact solution in the Josephson junction line as an unperturbed state. (Auth.)