Low noise amplifier for microphone
US5589799A · kind A · utility
30Cited by
11References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 23, 1995 |
| Grant date | Dec 31, 1996 |
| Priority date | — |
| Expiry date | May 23, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R25/502
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A preamplifier for use with high impedance audio frequency transducers, having two capacitance coupled stages each including a field effect transistor connected in follower mode. The two stages provide an impedance converter. The first field effect transistor is of substantially smaller geometry than the second, providing a low noise, low input capacitance. The second stage further reduces output impedance while maintaining low power supply feedthrough. A capacitor connected in shunt between the stages is employed for frequency shaping.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.