| Zugriffsnummer | 23536 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Improved setup for pulse-driven AC Josephson voltage standards [poster] |
| Autor(in); Institution |
Kieler, Oliver; 2.4, Quantenelektronik, PTB-Braunschweig
Schleußner, Detlef; 2.6, Elektrische Quantenmetrologie, PTB-Braunschweig
Behr, Ralf; 2.6, Elektrische Quantenmetrologie, PTB-Braunschweig
Kohlmann, Johannes; 2.4, Quantenelektronik, PTB-Braunschweig
|
| Quelle/Jahr | 12th International Superconductive Electronics Conference: Conference program and extended abstracts:(2009), HF-P21, 2 S. |
| Herausgeber(in) |
Enpuku, Keiji
|
| Verlag | Fukuoka: |
| Konferenzangaben | International Superconductive Electronics Conference - ISEC 2009, Fukuoka, 16-19, June, 2009, Japan |
| Zusammenfassung | An ac Josephson voltage standard system was established and optimized for the generation of quantized, arbitrary bipolar waveforms showing low distortion frequency spectra. This Josephson Arbitrary Waveform Synthesizer (JAWS) is based on pulse-driven sub-µm SNS-type Josephson junctions (S: Superconductor, N: Normal metal). In order to further improve the quality of the generated waveforms, we investigated the influence of the SD-code amplitude and length as well as the phase shifter used on stability and operation margins of the ac waveforms. High quality waveforms with low distortion were generated up to code amplitudes of 99 %. To generate bipolar waveforms in a more comfortable way, we furthermore investigated a ternary bit-stream generator. Applying these ternary codes to lumped Josephson arrays we were able to achieve high quality bipolar waveforms by adjusting only one parameter: the pulse amplitude. The influence of the SD-code amplitude and code length is investigated for this experimental setup, too. As a consequence of this modified setup, the time stability of the signal is quite high even with small current margins. Due to the larger code memory, it was possible to synthesize ac waveforms with frequencies down to 156 Hz. |
