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Broadband S-parameter characterization of a DC-SQUID amplifier



Leonardo M. Ranzani, Lafe F. Spietz, Jose A. Aumentado


In this work we characterize the 2-port scattering parameters of a superconducting quantum interference device (DC-SQUID) ampli er at 20 mK in the 2{8 GHz band. The measurement reference plane is positioned on a 6.25 microstrip line situated directly at the input and output of the device by means of a thru-reflect-line cryogenic calibration procedure. From the scattering parameters, we derive the device available power gain, isolation and input impedance over the 2{8 GHz range. This measurement methodology provides a path towards designing wide-band matching circuits for low impedance superconducting ampli ers operating at dilution refrigerator temperatures.
Applied Physics Letters


Ranzani, L. , Spietz, L. and Aumentado, J. (2013), Broadband S-parameter characterization of a DC-SQUID amplifier, Applied Physics Letters, [online], (Accessed May 26, 2024)


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Created July 8, 2013, Updated October 14, 2020