Traveling wave parametric amplifiers with inbuilt reverse isolation, Part I

Traveling wave parametric amplifiers (TWPAs) have emerged as critical tools for near-quantum-limited broadband amplification of microwave signals. Typically these amplifiers suffer from unavoidable reflections and non-zero backward emission. Thus requiring additional isolation between the device under test (DUT) and the amplifier to protect the DUT from unwanted radiations. This not only makes the measurement setup considerably bulky but also introduces additional losses before the primary amplifier, resulting in the degradation of the noise performance of the amplification chain.

We will present our efforts towards building a Josephson-junction-based TWPA that utilizes nonlinearities not only for amplification but also to upconvert backward propagating modes to a frequency band that can be easily discarded, effectively providing reverse isolation. This should help in improving the noise performance of the amplification chain while making it compact and better suited for upscaling the multiplexed measurement setups.