INTEGRATED RESONANT MICROBEAM SENSOR AND TRANSISTOR OSCILLATOR

摘要

At least one microbeam situated on a substrate, having a resonant frequencydependent on the strain on the microbeam which maybe affected by the bending of the substrate. The beam or beams have sense anddrive electrodes proximate to the beam or beams andform capacitors with a beam being the other electrode. The capacitance variesas the beam moves in vibration. The sense electrode isconnected to an input of a transistor, such as the gate or base, and the driveelectrode is connected to an output of the transistor. Thetransistor has a load impedance with a capacitive component to aid in thesustaining of vibration of the beam at a resonant frequency. Ahigh ohm resistor is connected between the gate and the drain of thetransistor to appropriately bias the gate. The bending of the substratemay be caused by a magnitude of a physical stimulus being measured. However,the bending of the substrate is not utilized nor desiredin the filter and temperature sensing configurations of the invention. Thefrequency of resonance is an indication of the magnitude of thephysical parameter. Variants of the sensor may be implemented with differentplacements of the sense and drive electrodes, and additionalelectronics as needed to implement the various configurations and microbeamgeometry. Additional sense and/or drive electrodes and beamsalso may be incorporated in the transistor resonant microbeam sensor.