US 10,649,015 B1 · Capacitive sensor including compensation for phase shift

Abstract

A method may include applying an excitation signal to a capacitor of the capacitive sensor which causes generation of a modulated signal from an input signal indicative of a variance in a capacitance of the capacitor, detecting the modulated signal with a detector to generate a detected modulated signal that has a phase shift relative to the excitation signal, demodulating the detected modulated signal into an in-phase component and a quadrature component using a reference signal, nullifying the quadrature component by setting a phase of the reference signal relative to the excitation signal to compensate for the phase shift, and outputting the in-phase component as an unmodulated output signal representative of the capacitance.

Claims16

Dependent claims

A method of measuring a capacitive sensor, the method comprising:

applying, by an excitation source, an excitation signal to a capacitor of a capacitive sensor which causes generation of a modulated signal from an input signal indicative of a variance in a capacitance of the capacitor;
detecting, by a detector, the modulated signal with a detector to generate a detected modulated signal that has a phase shift relative to the excitation signal;
demodulating, by a demodulator, the detected modulated signal into an in-phase component and a quadrature component using a reference signal;
nullifying, by a controller, the quadrature component by setting a phase of the reference signal relative to the excitation signal to compensate for the phase shift;
and
outputting, by an output, the in-phase component as an unmodulated output signal representative of the capacitance.

3 more elements

Dependencies are inferred from the claim text.

Capacitive sensor including compensation for phase shift

Life of this patent

Capacitive sensor including compensation for phase shift

Life of this patent

Abstract

Claims16