Bulk acoustic wave resonator based wireless and passive pressure sensor

摘要

In this work, a wireless and passive pressure sensor based on film bulk acoustic wave resonator (FBAR) has been proposed and investigated experimentally. Finite element analysis (FEA) was performed to determine the vibration mechanism and modes of the film in the device. The FBAR device was fabricated using traditional MEMS process and the pressure sensor was obtained by sealing the back-etched cavity of the device on a glass substrate. The network analyzer was used to characterize the wireless and passive performance of the sensor. The results showed that the pressure variation of the surroundings can be detected by measuring the frequency shift of the sensor wirelessly. The sensor has a fast response time of about 1 s, and a pressure sensitivity of 1.5 ppm/kPa with an excellent linearity of 0.997 in the pressure range from 17 kPa to 200 kPa at the temperature of 25 degrees C. Moreover, the sensor also possesses an excellent linearity frequency response with temperature change, demonstrated its potential for wireless passive sensing applications.