Two-line Josephson traveling wave parametric amplifier

Feasibility of two-line design of Josephson traveling wave parametric amplifier aimed at increase of the allowed pump wave energy and hence the gain growth is analyzed and discussed. Serious restrictions follow from both the cyclic energy transfer of the pump, signal and idler waves in the coupled waveguide lines and the phase mismatch of the waves. Besides, impact of the artificial line discreteness on the phase mismatch is considered as well.