Oscillation circuit and a communication semiconductor integrated circuit
US6906596B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 25, 2002 |
| Grant date | Jun 14, 2005 |
| Priority date | — |
| Expiry date | Dec 28, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/101
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A voltage controlled LC resonance oscillation circuit has a plurality of capacitive elements connected to an output node. These capacitive elements are applied with voltages at opposing terminals for selecting an oscillating frequency band, so that the oscillating frequency band can be changed step by step in accordance with the selection voltage. The capacitive elements include at least one variable capacitive element such as a MOS capacitor, the capacitance of which is varied in accordance with a voltage applied thereto. The MOS capacitor is similar in structure to a MOS transistor. The variable capacitive element can be supplied at a terminal opposite to the output node with a voltage from a variable voltage source, for example, in place of the selection voltage. The voltage controlled LC resonance oscillation circuit can measure the output amplitude and oscillating frequency without affecting the characteristics thereof, and reduce the parasitic capacitance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.