Akim Babenko, Nathan Flowers-Jacobs, Anna Fox, Paul Dresselhaus, Zoya Popovic, Samuel P. Benz
This paper presents a superconducting voltage source that generates microwave modulated waveforms with quantum-based stability. The voltage source - an RF Josephson Arbitrary Waveform Synthesizer (RF-JAWS) - uses a superconducting IC with an array of 4500 series-connected Josephson junctions (JJs) that are embedded in a coplanar waveguide transmission line. The JJs are driven with current pulses that force each JJ to generate voltage pulses with a quantized integrated area. A pulse sequence is created using a delta-sigma algorithm to generate a 101-tone waveform with a 40 MHz instantaneous bandwidth around 1.005 GHz with a flat power distribution of -53 dBm and a Schroeder phase distribution. The JJ's quantum-based nonlinearity produces an amplitude stability with respect to various drive and bias parameters of ±0.005 dB and a detrended phase stability of ±0.05°. Another delta-sigma pulse sequence generates a 10 MHz Quadrature-Phase-Shift-Keying (QPSK) waveform on a 1.005 GHz carrier that has the same stability and the mean error vector magnitude of -48 dB. This work is a step toward creating a reference source for power and cross-frequency phase calibrations, as well as a reference modulated-signal source for calibrating telecommunication links.
IEEE Transactions on Microwave Theory and Techniques
, Flowers-Jacobs, N.
, Fox, A.
, Dresselhaus, P.
, Popovic, Z.
and Benz, S.
Quantum-Based Microwave Modulated Waveforms, IEEE Transactions on Microwave Theory and Techniques, [online], https://doi.org/10.1109/TMTT.2023.3297364, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935292
(Accessed February 24, 2024)