Demodulator
US6363126B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1998 |
| Grant date | Mar 26, 2002 |
| Priority date | — |
| Expiry date | Dec 11, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0065
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The invention presents an apparatus capable of demodulating stably if there are time-course changes in the constituent parts in a demodulator of digital modulated signal. This demodulator comprises an operator for setting the oscillation frequency of a local oscillator 2, and within a passing frequency band of a band pass filter BPF 3, the operator controls the local oscillator 2 so that the frequency of the output signal of a first mixer 1 may settle within a control band in a controllable frequency band of an AFC feedback loop composed of an orthogonal detector 4, a carrier regenerator 9, a frequency error detector 10, a frequency controller 11, a signal selector 12, a D/A converter 13, and a VCO 14, and a local carrier is issued from the local oscillator 2 to the first mixer 1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.