Microphone amplifier detector
US5023616A · kind A · utility
0Cited by
4References
8Claims
0Family size
Inventor
Key dates
| Filing date | Aug 25, 1967 |
| Grant date | Jun 11, 1991 |
| Priority date | — |
| Expiry date | Aug 25, 1987 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device for detecting a covert transmitter having a time varying impedance therein including a radio frequency transmitter and an audio frequency transmitter which are directed so as to illuminate a target area. The audio tone drives the active elements into a non-linear mode of operation to modulate the transmitted radio frequency. The re-radiated energy is detected by a further radio frequency receiver.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.