Title :
Performance Improvements for the NIST 1 V Josephson Arbitrary Waveform Synthesizer
Author :
Benz, Samuel P. ; Waltman, Steven B. ; Fox, Anna E. ; Dresselhaus, Paul D. ; Rufenacht, Alain ; Howe, L. ; Schwall, Robert E. ; Flowers-Jacobs, N.E.
Author_Institution :
Nat. Inst. of Stand. & Technol., Boulder, CO, USA
Abstract :
The performance of the NIST Josephson arbitrary waveform synthesizer has been improved such that it generates a root-mean-square (rms) output voltage of 1 V with an operating current range greater than 2 mA. Our previous 1 V JAWS circuit achieved this same maximum voltage over a current range of 0.4 mA by operating every Josephson junction in its second quantum state. The newest circuit synthesizes 1 V waveforms with the junctions operating in the first quantum state. The voltage per array is doubled because the number of junctions in each array was doubled through the use of improved microwave circuit designs that increased the bias uniformity to the junctions. We describe the circuit improvements and device operation, and we demonstrate the system capabilities by showing measured spectra of a 1 Hz sine wave and a dual-tone waveform. With only two arrays of the new circuit, we also synthesized a 128 mV sine wave without a compensation bias signal, which is one of the bias signals required for achieving 1 V. This is the same rms output voltage achieved with the previous circuit using four arrays.
Keywords :
Josephson effect; microwave circuits; superconducting junction devices; superconducting microwave devices; waveform generators; Josephson arbitrary waveform synthesizer circuit; Josephson junction; NIST Josephson arbitrary waveform synthesizer performance; bias uniformity; circuit arrays; compensation bias signal; current 0.4 mA; device operation; dual-tone waveform; frequency 1 Hz; maximum voltage; microwave circuit designs; operating current; quantum state; root-mean-square output voltage; sine wave; voltage 1 V; voltage 128 mV; Government; Digital-analog conversion; Josephson arrays; quantization; signal synthesis; standards; superconducting integrated circuits; voltage measurement;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2014.2364137