Title :
HTS mixers based on the Josephson effect and on the hot-electron bolometric effect
Author :
Harnack, O. ; Beuven, S. ; Darula, M. ; Kohlstedt, H. ; Tarasov, M. ; Stephansov, E. ; Ivanov, Z.
Author_Institution :
Inst. for Thin Film & Ion Technol., Res. Center Julich, Germany
fDate :
6/1/1999 12:00:00 AM
Abstract :
We report on our experimental studies of high-T/sub c/ Josephson mixers and high-T/sub c/ hot-electron bolometric (HEB) effect mixers. Mixers based on high-T/sub c/ bicrystal Josephson junctions have been fabricated, and noise, conversion efficiency, and receiver bandwidth measurements have been performed in the frequency range between 90 and 550 GHz. The dependence of the mixer performance on the operation temperature has been studied. High-T/sub c/ HEB mixers have been fabricated on MgO and sapphire substrates. We successfully sized the dimensions of the effective device volume down and managed to fabricate 50-60 nm long devices. In such short structures phonon diffusion into the normal metal electrodes should significantly improve the mixer performance.
Keywords :
Josephson effect; bolometers; high-temperature superconductors; hot carriers; millimetre wave mixers; superconducting mixers; 90 to 550 GHz; Al/sub 2/O/sub 3/; Josephson mixer; MgO; MgO substrate; bicrystal Josephson junction; conversion efficiency; high-T/sub c/ superconductor; hot electron bolometric mixer; noise; phonon diffusion; receiver bandwidth; sapphire substrate; Bandwidth; Frequency conversion; Frequency measurement; High temperature superconductors; Josephson effect; Josephson junctions; Mixers; Noise measurement; Performance evaluation; Temperature dependence;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
