Abstract
We have been developing an analog amplifier utilizing a flux flow phenomenon in a Josephson line. i.e., Flux-Flow-Type Josephson Amplifier (FFA). The FFA converts a signal current Isto a voltage VDCacross the Josephson line, and the Is-Vdccharacteristic determines performances of FFA. such as a gain and a saturation level. Studies have been made to improve the Is-Vdcrelation, such as a transresistance r.=dVdc/dI and a linear operation range. It is shown that the transresistance can be improved significantly by reducing a width W of the Josephson line, and by utilizing a kinetic inductance of the line. The kinetic inductance can be increased by thinning the thickness t of an electrode of the line, and by using the electrode with large London penetration depth such as NbN. The obtained transresistance is as large as r.=6.8Ω for NbN/Pb-alloy Josephson lines with t=5nm and W=4μm. It is also shown that the linear operation range of the amplifier is as large as lmV. On the basis of experimental results, evaluation is made of the performances of FFA.
| Original language | English |
|---|---|
| Pages (from-to) | 1266-1269 |
| Number of pages | 4 |
| Journal | IEEE Transactions on Magnetics |
| Volume | 25 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Mar 1989 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering