A compact design for the Josephson mixer: the lumped element circuit

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We present a compact and efficient design in terms of gain, bandwidth and dynamical range for the Josephson mixer, the superconducting circuit performing three-wave mixing at microwave frequencies.

• In an all lumped-element based circuit with galvanically coupled ports, we demonstrate non degenerate amplification for microwave signals over a bandwidth up to 50 MHz for a power gain of 20 dB.
• The quantum efficiency of the mixer is shown to be about 70$\%$ and its saturation power reaches $-112$ dBm.