Theory of Multiwave Mixing within the Superconducting Kinetic-Inductance Traveling-Wave Amplifier
David P. Pappas, Robert P. Erickson
We present the theory of parametric mixing within the coplanar waveguide (CPW) of a super- conducting nonlinear kinetic-inductance traveling-wave (KIT) ampli er engineered with periodic dispersion loadings. We develop a metamaterial band theory of the dispersion-engineered KIT using a Floquet-Bloch construction and apply it to the description of mixing of nonlinear RF trav- eling waves. Our theory allows us to calculate signal gain vs. signal frequency in the presence of a frequency stop gap based solely on patterned loading design. Our results for both three-wave mixing (3WM), with applied DC, and four-wave mixing (4WM), without DC, compare favorably with experiment. In particular, our theory predicts an intrinsic origin to undulations of 4WM signal gain with signal frequency, apart from extrinsic sources, such as impedance mismatch, and shows that such undulations are absent from 3WM signal gain achievable with DC. Our work is extensible to ampli ers based on Josephson junctions in a lumped LC transmission line (TWPA).
and Erickson, R.
Theory of Multiwave Mixing within the Superconducting Kinetic-Inductance Traveling-Wave Amplifier, Physical Review B, [online], https://doi.org/10.1103/PhysRevB.95.104506
(Accessed February 27, 2024)