Frequency synthesizer
AssigneeSeiko Epson Corporation
InventorsMasayoshi Todorokihara, Aritsugu Yajima, Tetsuro Matsumoto
Life of this patent
Estimating the term…
Abstract
A frequency synthesizer includes: an oscillating section that generates a first signal; a frequency ratio measuring section that measures a frequency ratio of the first signal and a second signal by using the first signal and the second signal; a comparing section that compares the frequency ratio, which is measured by the frequency measuring section, with a target value of a frequency ratio; and a filter that is disposed on a preceding stage of the comparing section. A frequency of the first signal of the oscillating section is adjusted on the basis of a comparison result of the comparing section.
Claims16
A frequency synthesizer comprising:
- an oscillating section that generates a first signal;
- a frequency ratio measuring section that measures a frequency ratio of the first signal and a second signal, which is different from the first signal, by using the first signal and the second signal;
- a comparing section that compares the frequency ratio, which is measured by the frequency ratio measuring section, with a target value of a frequency ratio;
- and
- a filter that is disposed on a succeeding stage of the frequency ratio measuring section,
- wherein a frequency of the first signal of the oscillating section is adjusted based on a comparison result of the comparing section, and
- the frequency ratio measuring section has a frequency delta sigma modulation section that is configured to perform frequency delta sigma modulation on one of the first signal and the second signal based on the other of the first signal and the second signal.
Dependencies are inferred from the claim text.