Impedance-to-voltage converter
US6335642B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 22, 1999 |
| Grant date | Jan 1, 2002 |
| Priority date | — |
| Expiry date | Sep 22, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/2605
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A impedance-to-voltage converter for converting an impedance of a target to a voltage is described which comprises an operational amplifier (OP), a coaxial cable consisting a signal line and shielding element(s), and an AC signal generator. A feedback impedance circuit is connected between output and inverting terminals of the OP, and whereby a non-inverting terminal and the inverting terminal are an imaginal-short condition. One end of the signal line is connected to the inverting input terminal of the OP and the other end is connected to one electrode of the target and the AC signal generator is connected to the non-inverting input terminal of the OP. The shielding element comprises at least one shielding layer surrounding the signal line and is connected to the non-inverting input terminal of the OP, and thus the signal line and the shielding layer are the same voltage due to the imaginal-short of the input terminals of the OP, resulting in reduction of noise on the signal line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.