Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 49: Poster Session: Superconductivity

TT 49.23: Poster

Mittwoch, 3. April 2019, 15:00–18:30, Poster D

Development of RF-Power Dividers for the Josephson Arbitrary Waveform Synthesizer — •Hao Tian, Oliver Kieler, Ralf Behr, Rüdiger Wendisch, Rolf-Werner Gerdau, Karsten Kuhlmann, and Johannes Kohlmann — Physikalisch-Technische Bundesanstalt, Braunschweig, Germany

The JAWS, based on pulse-driven series arrays of SNS Josephson Junctions (JJs) at 4 K, enables spectrally pure AC voltages to be synthesized from DC up to MHz. To make the experimental set-up less complex and to increase the JJs operated by a single PPG channel, we designed two types of on-chip power dividers. One type is a serial-parallel power divider, the second type is a Wilkinson power divider. Each output of the power divider is equipped with a DC-block capacitor. Different designs were simulated, integrated to JJs arrays and fabricated. The results showed that the test chips containing a 2-stage serial-parallel power divider and 2000 JJs are operational up to a maximal clock frequency of 8 GHz. However, the operation margins are rather small and spectrally pure sinusoidal waveforms could be synthesized with sigma-delta code amplitudes < 30%. The 1-stage Wilkinson power divider with 1000 JJs is operating up to a clock frequency of 15 GHz. We successfully synthesized spectrally pure output voltages of 11.7 mV (RMS). The operation margins are much larger than for the previous design.

This work was partly supported by the EMPIR programme co-financed by the Participating States and from the EU H2020 programme (JRP 15SIB04 QuADC) and by the German BMWi (project ZF4104104AB7).