ELECTRICAL CROSS-TALK IN 2-PORT RESONATORS - THE RESONANT SILICON BEAM FORCE SENSOR

An important design consideration in the development of two-port resonant sensors is the electrical cross-talk between the input port and the output port. The overall transfer function HBAR(j-omega) of the two-port sensor is equal to the vectorial sum of a transfer function representing the mechanical behavior and a transfer function representing the electrical cross-talk. The resonant silicon beam force sensor with a piezoelectric driver and a piezoelectric detector is analyzed. Two solutions to reduce the level of cross-talk are presented. Proper adjustment of the value of relevant components in the sensor geometry and/or electrical interruption of the bottom electrode result in a cross-talk level close to the noise level for the frequency range of interest.