Transmitter with a phase modulator and a phase locked loop
US6420940B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 2000 |
| Grant date | Jul 16, 2002 |
| Priority date | — |
| Expiry date | Aug 14, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M3/452
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A transmitter has a phase modulator and a phase locked loop that has a relatively high powered voltage controlled oscillator. The phase locked loop has a phase sensitive detector for comparing a phase comparison frequency derived from the voltage controlled oscillator output with a phase modulated intermediate frequency carrier derived from the phase modulator. The phase modulator has a reference frequency source, means for deriving four quadrature phase components of the reference frequency produced by the source and phase selection means controlled by complex modulation means for deriving the phase modulated intermediate frequency carrier by random interpolation between the four quadrature components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.