Traceable Validation of Calculable Quantum-Based RF Waveforms

We compare the calculated, quantum-based output of a radio-frequency Josephson arbitrary waveform synthesizer (RF-JAWS) with its measured output that is calibrated through the established NIST RF power traceability path, a necessary first step towards quantum-based RF metrology. An array of
1,500 Josephson junctions (JJs) is used to synthesize sinusoids from 50 MHz to 3 GHz, each with a nominal output power of -49.67 dBm and a demonstrated quantum-locking range (QLR) exceeding 1 mA. We perform a two-tier calibration of two-port vector network analyzer (VNA) measurements of the RF-JAWS waveforms with uncertainty analysis: (1) the VNA wave parameters are referenced to a NIST-calibrated coaxial power sensor, and (2) a cryogenic probe station, together with on-chip superconducting calibration standards, establishes an on-chip reference plane at the JJ-array. The calibrated measurement of the forward- and backward-propagating power is compared with the expected, calculated outputs, and, after accounting for high-frequency roll-off, we observe agreement within the expanded (k = 2) uncertainty limits for most frequencies. The data are generated here from the two figures presented in this work. Figure 1 validates the quantum-based generation of all waveforms synthesized in the paper using a dc-bias quantum-locking range. Figure 2 presents the main result of the paper: for all synthesized waveforms, the JAWS-calculated output is compared with the two-tier calibrated VNA measurements, with expanded uncertainties reported for all values.