The suppression efficiency of the correlated noise and drift of self-oscillating front-end circuit in a pseudo-differential eddy-current displacement sensor (ECDS) is investigated using COMSOL and MATLAB. The transfer characteristic of the sensor coil, excited at 200 MHz, is obtained through a FE model in COMSOL. The characteristic is linearized to a second-order fit around a standoff distance to the target (xso) of 55 μm. The nonlinearity of the interface is modelled in MATLAB. It is found that, in order to tolerate 1% drift in the oscillator amplitude, a maximum 2nd harmonic distortion (HD2) of the interface has to be less than −72 dB when the sensor HD2 is −51.5 dB for 5 μm displacement range around xso = 55 μm.
|Number of pages||4|
|Publication status||Published - 1 Sep 2016|
|Event||Eurosensors 2016: The 30th anniversary Eurosensors Conference - Budapest, Hungary|
Duration: 4 Sep 2016 → 7 Sep 2016
- finite elelement