Signal demodulator using a multiplying digital-to-analog converter
US4611177A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 26, 1985 |
| Grant date | Sep 9, 1986 |
| Priority date | — |
| Expiry date | Aug 26, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03D1/22
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
By using a multiplying digital-to-analog converter for signal demodulation in the disclosed detection scheme, the demodulating signal from the local oscillator can be in digital form without seriously affecting the detected, or demodulated, output. Specifically, a multiplying digital-to-analog converter (DAC) is used for detection. The multiplying DAC accepts an analog input for demodulation or detection and a signal in the form of a repeating string of digital values as the demodulating input. Sensitive, and therefore inherently unstable, filters generally required in the prior art to prefilter the demodulating signal to reduce undesirable higher harmonics are therefore not required, thus reducing one major source of instability in a detection system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.