Method to control amplitude and phase of a signal
US11569817B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 2020 |
| Grant date | Jan 31, 2023 |
| Priority date | — |
| Expiry date | Aug 6, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/96073
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for generating an offset signal for a capacitive sensor includes a waveform generator configured to generate a waveform, an R-2R ladder circuit having a constant output resistance that is coupled to an output of the waveform generator and is configured to generate the offset signal based on the waveform, and an adjustable capacitor that is connected between an output of the R-2R ladder circuit and a reference voltage. The capacitive sensor includes one or more sensing electrodes coupled to the waveform generator through a capacitance and is configured to generate a sensed signal by sensing an object. The R-2R ladder circuit and the adjustable capacitor are configured to adjust amplitude and phase of the offset signal such that the amplitude and the phase of the offset signal respectively coincide with an amplitude and a phase of the sensed signal when the sensing electrodes do not sense the object.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.