Synchronous signal detection apparatus with a photoconductive photodetector
US5591962A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 1995 |
| Grant date | Jan 7, 1997 |
| Priority date | — |
| Expiry date | Jul 6, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/60
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A photoconductive photodetector to which a modulation voltage signal having a predetermined frequency is applied receives a signal to be measured (I.sub.I) while adjusting the phase of a modulation signal by a phase shifter. A current-to-voltage conversion unit extracts a DC component of a current signal generated at the photoconductive photodetector in correspondence with the intensity of a predetermined frequency component of the signal to be measured (I.sub.I) as a voltage signal. The maximum value of DC voltage values (V.sub.O) obtained in every setting operation of a phase adjustment value is identified. The maximum value corresponds a case in which the modulation voltage signal and the predetermined frequency component of the signal to be measured (I.sub.I) are in phase. The intensity of the predetermined frequency component of the signal to be measured (I.sub.I) is calculated. As a result, a high-speed phenomenon can be measured with a high precision.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.