Electronic device for controlling a reactance value for a reactive element
US5777522A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1997 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Jan 3, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J2200/10
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A capacitor (200) having an actual physical capacitance value of Cact and is coupled to an oscillator (36). The oscillation frequency of the oscillator (36) can be changed by changing the effective capacitance of the capacitor (200). The actual capacitance (Cact) of capacitor (200) can be altered to appear to be any effective capacitance (Ceff) between zero and a value much greater than Cact by using a Miller effect. In order to alter the effective capacitance of the capacitor (200), a representation of the output osculation signal (16) is provided to a frequency adjust stage (22). The frequency adjust stage either passed the signal (16) with 0.degree. phase shift or with 180.degree. phase shift. In addition to shifting the phase, the stage (22) will amplify or attenuate the signal (16) to result in the phase shifted and amplified/attenuated frequency adjusting signal (24). By providing the signals (16 and 24) to opposite ends of the capacitor (200), Miller affect will alter the effective capacitance of the capacitor (200) thereby altering a frequency of the oscillator (36).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.