Voltage controlled oscillator
US7268636B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 14, 2005 |
| Grant date | Sep 11, 2007 |
| Priority date | — |
| Expiry date | Jul 21, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/099
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a voltage controlled oscillator including an amplifier, a feedback circuit and a crystal oscillator, two MOS transistors M1, M2 are connected for use as variable capacity elements for the frequency adjustment of the voltage controlled oscillator. Drains of the MOS transistors M1, M2 are respectively connected to an XT terminal and an XTB terminal of the crystal oscillator. Sources of the MOS transistors M1, M2 are made common and connected to a grounding terminal via a capacitor C3. Gates of the MOS transistors M1, M2 are made common, and an added voltage signal of a temperature compensating signal voltage and an external frequency control signal voltage is applied to the common gate terminals of the MOS transistors to thereby perform the frequency control of the oscillator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.