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Resonance-free Low-pass Filters for the ac Josephson Voltage Standard



Michio Watanabe, Paul Dresselhaus, Samuel Benz


We have designed and characterized superconducting integrated circuits for the ac Josephson voltage standard that demonstrate significantly improved performance. The typical circuit consists of an array of superconductor-normal metal-superconductor Josephson junctions, which are placed in a transmission line and biased with a broadband (dc-to-15 GHz) pulse-drive waveform. Additional low speed (dc and audio frequency) bias and output leads that connect to the array, contain on-chip inductors that act as low-pass filters. The array operating margins were improved by adding resistive shunts across these inductors which damp their intrinsic resonances. These resonances had previously degraded the integrity of the broadband signal driving the array. We present simulations and measurements of these improved circuits that demonstrate no resonances in the range of 0.1'20GHz. Moreover, the operating margins of the ac Josephson voltage standard were improved.
IEEE Transactions on Applied Superconductivity


Josephson devices, microwave circuits, standards, voltage.


Watanabe, M. , Dresselhaus, P. and Benz, S. (2006), Resonance-free Low-pass Filters for the ac Josephson Voltage Standard, IEEE Transactions on Applied Superconductivity, [online], (Accessed April 15, 2024)
Created February 28, 2006, Updated October 12, 2021