An electrothermally excited dual beams silicon resonant pressure sensor with temperature compensation

摘要

An electrothermally excited dual beams silicon resonant pressure sensor with temperature compensation is proposed in this paper. One beam locates upon the diaphragm, whose resonant frequency changes with the measured pressure; the other beam is on the fixed edge, isolated from the pressure effect but sensitive to the temperature variation. Taking the difference of the dual beams' resonant frequencies, temperature influence can be corrected. Compensation algorithm with consideration of the fabrication errors is deducted theoretically and implemented by a homemade readout system. Experimental results of the test sample indicates that the maxim pressure measurement residual errors without compensation is up to 53.9 kPa in the working temperature range from -40 to 60℃; while with compensation the maxim residual errors decreased to 1.8 kPa from -40 to 60℃, which is only 3.3% of the uncompensated sensor. The experimental results confirm that the new designed sensor has good temperature compensation ability.