Self-calibrating tunable filter
US7050781B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 2002 |
| Grant date | May 23, 2006 |
| Priority date | — |
| Expiry date | Mar 13, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J2200/29
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Some embodiments of the present invention include a circuit in a wireless transmitter or other apparatus is automatically calibrated using a calibration circuit to accommodate provide a desired characteristic such as a filter response, where the component values of the filter circuit may vary such as in an integrated circuit. In one embodiment, the calibration circuit is coupled to one or more adjustable capacitors in the filter circuit to select a capacitor value so that the filter circuit exhibits the desired filter response. In one particular embodiment, the adjustable capacitor is charged in an RC circuit for each clock cycle at power up. The value of the adjustable capacitor is changed for each clock cycle until the capacitor charges to a level greater than or equal to predetermined reference voltage. When the capacitor is charged to a predetermined reference voltage, a desired capacitance value is indicated, and the adjustable capacitor is maintained at the desired capacitance value to provide the desired filter output. The calibration circuit causes the circuit to be self-calibrating to the desired characteristic such as a desired filter response. Other embodiments are descr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.