Enhanced LC filter with tunable Q
US6307442A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 17, 1999 |
| Grant date | Oct 23, 2001 |
| Priority date | — |
| Expiry date | May 17, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J2200/18
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tunable electronic filter circuit is provided including an input terminal and an output terminal connected to the input terminal with a node therebetween. An inductor, a variable capacitor, and a variable resistor are connected between the node and ground. Coupled to the variable capacitor and the variable resistor is a feedback control circuit. The feedback control circuit is operable to tune the variable capacitor in order to set a predetermined frequency, or center frequency, of the electronic filter circuit. The feedback control circuit is further operable to tune the variable resistor in order to calibrate a quality factor of the electronic filter circuit. In use when an input signal is applied to the input terminal, the electronic filter circuit passes an output signal to the output terminal. Such output signal includes components of the input signal within a predetermined frequency bandwidth set by the predetermined frequency and filters out other components of the input signal. As an option, a "slave" tunable electronic filter circuit may be providing including a variable capacitor and a variable resistor which are also controlled by the feedback circuit. This allows the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.