Tuning Range of the Backward Traveling-Wave Parametric Amplifier (Correspondence)

Experimental results obtained with backward traveling-wave parametric amplifiers indicate that their tuning range is greater than that predicted when TEM propagation is assumed. An analytical and graphical examination of the possible tuning range when non-TEM transmission lines are considered is given below. This examination shows how the tuning range may be optimized, and indicates what the maximum range would be using realizable transmission lines.