Symmetric Traveling Wave Parametric Amplifier

We developed and experimentally tested a Symmetric Traveling Wave Parametric Amplifier (STWPA) based on Three-Wave Mixing, using the new concept of a Symmetric rf- SQUID. This allows to fully control the second and third order nonlinearities of the STWPA by applying external currents. In this way, the optimal bias point can be reached, taking into account both phase mismatch and pump depletion minimization. The structure was tested at 4.2K, showing a 4GHz bandwidth and a maximum estimated gain of 17dB. STWPA showed also great flexibility, allowing up-down conversion mixer operations and rf-controlled switch.