Superconducting traveling wave parametric amplifiers (TWPAs) are broadband near-quantum limited microwave amplifiers commonly used for qubit readout and a wide range of other applications in quantum technologies. The performance of these amplifiers depends on achieving impedance matching to minimize reflected signals. Here, we apply a microwave calibration technique to extract the S-parameters of a Josephson junction based TWPA in-operando. This enables reflections occurring at the TWPA and its extended network of components to be quantified, and we find that the in-operation performance can be well described by the off-state measured S-parameters.

中文翻译：

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Josephson 行波参量放大器的原位微波散射参数校准测量


超导行波参量放大器 （TWPA） 是宽带近量子极限微波放大器，通常用于量子比特读出和量子技术中的各种其他应用。这些放大器的性能取决于实现阻抗匹配，以最大限度地减少反射信号。在这里，我们应用微波校准技术来提取基于 Josephson 结的 TWPA 操作符的 S 参数。这使得 TWPA 及其扩展组件网络处发生的反射可以被量化，我们发现运行中的性能可以用关断状态测量的 S 参数很好地描述。