Specific nearby electronic scheme for multiplexed excitation and detection of piezoelectric silicon-based micromembranes resonant frequencies using FPGA technology

A new concept for a precise compensation of the static capacitance of piezoelectric silicon-based micromembranes is proposed. Combining analogue and digital (FPGA) hardware elements with specific software treatment, this system enables the parallel excitation and detection of the resonant frequencies (and the quality factors) of piezoelectric silicon-based micromembranes integrated on the same chip. The frequency measurement stability is less than 1 ppm (1-2 Hz) with a switching capability of 4 membranes/sec and a measurement bandwidth of 1.5 Mhz.