| Autor: |
Donnelly CA; Superconductive Electronics Group, National Institute of Standards and Technology (NIST), Boulder, CO 80305 USA.; Department of Electrical Engineering, Stanford University, Stanford, CA 94305 USA., Brevik JA; Superconductive Electronics Group, National Institute of Standards and Technology (NIST), Boulder, CO 80305 USA., Dresselhaus PD; Superconductive Electronics Group, National Institute of Standards and Technology (NIST), Boulder, CO 80305 USA., Hopkins PF; Superconductive Electronics Group, National Institute of Standards and Technology (NIST), Boulder, CO 80305 USA., Benz SP; Superconductive Electronics Group, National Institute of Standards and Technology (NIST), Boulder, CO 80305 USA. |
| Abstrakt: |
We present the first jitter sensitivity analysis of a superconducting voltage reference waveform synthesizer with fundamentally accurate output pulses. Successful deployment of a reference waveform source at microwave frequencies will represent a new paradigm for radio frequency metrology. The programmable waveform synthesizer considered in this paper contains a 1.5 bit delta-sigma digital-to-analog converter (DAC) with a sampling frequency of 28 GHz. We quantify the impact of random and deterministic output pulse position jitter (PPJ) on: 1) the amplitude accuracy of the output fundamental tone and 2) the in-band signal-to-noise and distortion ratio (SNDR). The superconducting DAC features a complete lack of output pulsewidth jitter, and random PPJ up to 200 fs rms has a negligible impact on accuracy and SNDR for synthesized tones up to 1 GHz. However, application of nonzero dc bias current is shown to produce deterministic PPJ of up to 5 ps, which, in turn, is shown to degrade the in-band SNDR by 30 dB at 1 GHz unless eliminated with techniques discussed in this paper. We verify the predicted effects of random and deterministic PPJ with simulations in the range of 100 kHz-1 GHz and with experiments in the range of 100 kHz-3 MHz. |
