Method and apparatus for frequency synthesis in direct-conversion transmitters
US7409192B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 2005 |
| Grant date | Aug 5, 2008 |
| Priority date | — |
| Expiry date | Feb 1, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/23
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for direct-conversion transmission generates a first frequency signal that is non-harmonically related to a transmit frequency signal, divides the first frequency signal to obtain a mixing frequency signal, divides the first frequency signal to obtain an intermediate frequency reference signal, generates the transmit frequency signal by using the mixing frequency signal to downconvert the transmit frequency signal into an intermediate frequency feedback signal, and phase-locks the intermediate frequency feedback signal to the intermediate frequency reference signal. The transmit frequency signal may be phase modulated, and may serve as an input to a saturated-mode power amplifier that can be configured for corresponding amplitude modulation. Alternatively, the un-modulated transmit frequency signal serves as the carrier signal input to a quadrature modulator, which imparts I/Q modulations to it, thereby producing a modulated carrier signal for input to a linear power amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.