Synthesizer and calibrating method for the same
US7180376B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 2005 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | Jun 13, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0898
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Synthesizer and calibrating method utilizing same. The frequency synthesizer modulates input signals comprising a phase locked loop circuit. The phase locked loop circuit comprises a phase frequency detector for generating a first signal, a low pass filter for outputting a filtered control signal derived from the received first signal, a voltage control oscillator for generating an output signal with a first frequency based on the control signal, a frequency divider dividing the first frequency for output to the input terminal of the phase frequency detector, a modulator coupled to the frequency divider, a pre-emphasis filter receiving and filtering the input signal for output to the modulator, and an auto loop gain calibration circuit, receiving the control signal, and calculating a current gain of the control signal in accordance with the voltage of the control signal to compensate for the frequency response mismatch between the pre-emphasis filter and the frequency synthesizer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.