Numerical analysis of a three-wave-mixing Josephson traveling-wave parametric amplifier with engineered dispersion loadings

Abstract

The recently proposed Josephson traveling-wave parametric amplifier (JTWPA) based on a ladder transmission line consisting of radio-frequency superconducting quantum interference devices and exploiting three-wave mixing has great potential in achieving both a gain of 20 dB and a flat bandwidth of at least 4 GHz. To realize this concept in practical amplifiers, we model the advanced JTWPA circuit with periodic modulation of the circuit parameters (engineered dispersion loadings), which allow the basic mixing process, i.e., [Formula: see text], where [Formula: see text], [Formula: see text], and [Formula: see text] are the signal, the pump, and the idler frequencies, respectively, and efficiently suppress propagation of unwanted higher tones, including [Formula: see text], [Formula: see text], [Formula: see text], etc. The engineered dispersion loadings allow achieving a sufficiently wide [Formula: see text] dB-bandwidth from [Formula: see text] to [Formula: see text] GHz combined with a reasonably small ripple ([Formula: see text] dB) in the gain-vs-frequency dependence.