Measurement method with synchronous subsampling

An electronic circuit arranged to be connected to a variable-excitation sensor for measuring a parameter, the electronic circuit comprising:

• synthesizer components arranged to use the same clock signal to produce both an excitation frequency, a sampling frequency, and an excitation signal at the excitation frequency, the excitation signal being applied as input to the variable-excitation sensor;
• and
• a digital envelope detector receiving as input a measurement signal that is produced by the variable-excitation sensor in response to the excitation signal, the digital envelope detector comprising:
• an analog-to-digital converter arranged to sample the measurement signal at the sampling frequency in such a manner as to produce sample points during successive observation windows, each observation window having a duration T and comprising a number Ns of sample points, the sample points being spaced apart by a sampling period Ts, the sampling period Ts and the duration T being such that:
• TS=NP·T0+(NT/NS)·T0 and T=NS·TS,
• where T0 is one excitation period of the excitation signal, where NP, NT, and NS are non-zero natural integers, and where NT is not a multiple of NS;
• and
• at least one processor component arranged to implement a synchronous demodulator arranged to produce, for each observation window, an output signal value on the basis of which the parameter is estimated.