Frequency synthesizer
US7888978B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 23, 2009 |
| Grant date | Feb 15, 2011 |
| Priority date | — |
| Expiry date | Mar 9, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/185
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A frequency synthesizer includes first and second frequency dividers for receiving and frequency-dividing a signal generated by a voltage-controlled oscillator, a frequency mixer for mixing output signals of the first and second frequency dividers, and a third frequency divider for receiving and frequency-dividing a signal having one frequency of two frequencies that are output by the frequency mixer. The first, second third and frequency dividers and the frequency mixer are provided in a feedback loop within a PLL circuit between the voltage-controlled oscillator and the phase comparator. The phase comparator has a first input terminal to which a signal to which a signal that is output by the third frequency divider is input and a second input terminal to which a reference clock signal that is output by a reference signal generator is input. A loop filter supplies the voltage-controlled oscillator with a voltage that is based upon result of the phase comparison by a phase comparator. The voltage-controlled oscillator supplies the first and second frequency dividers with a signal that oscillates at a frequency corresponding to the voltage input to the oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.