Frequency or phase modulation
US4870384A · kind A · utility
11Cited by
3References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 21, 1988 |
| Grant date | Sep 26, 1989 |
| Priority date | — |
| Expiry date | Dec 21, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03C3/0941
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency or phase modulator, in particular a DC-coupled frequency modulation synthesizer, comprises a voltage-controlled oscillator (1) in series with a divider (2) in a phase-locked loop, and an analog-to-digital converter (17) connected to control the divider in accordance with an input analog modulation signal. The converter (17), preferably a one-bit charge-balanced converter, has a noise-shaped frequency response to reduce noise at frequencies below the loop-bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.