Patent ID: 8063648

Claim:
A method for demodulating an output signal (y(t)) from a transducer ( 1 ) driven by an alternating excitation signal (u(t)) having an excitation frequency, said transducer ( 1 ) amplitude-modulating said output signal (y(t)) based on a quantity to be measured, the method comprising: receiving sampled values of the output signal from the transducer and sampled values of the excitation signal over at least one period of the excitation frequency, computing a first complex valued quantity ( Y ) including information on the amplitude and phase of the output signal at the excitation frequency based on said sampled values of the output signal from the transducer, computing a second complex valued quantity (Ū, Ī) including information on the amplitude and phase of the excitation signal at the excitation frequency based on said sampled values of the excitation signal, forming a complex valued output quotient between said first and second complex valued quantities, and computing a demodulated transducer output signal (O d ) based on said output quotient.