Surface Acoustic Wave Sensor Structure Simulation And Sensitive Characteristics Of Study

Due to its unique advantages such as high frequency, low volume, versatility, stability and mass production, Surface Acoustic Wave (SAW) device is successfully used in military and civilian fields including aerospace, mobile communication and electronic counter-measure, etc. The newly arisen SAW sensor is promising and gaining more and more attention for its high sensitivity and low power consumption. SAW sensor is widely used in sensitive detection of physical, chemical and biological measurands.The SAW technology in sensor applications has been reviewed. The transport model and the property of SAW in different piezoelectricity have been discussed. The frequency spectrum of one-path delayline resonance sensor has been simulated by MATLAB software. The characteristics of equal length and unequal length of IDT have been calculated. Remez exchange algorithm and the Firls optimization algorithm have been researched. Remez exchange algorithm has the merit that it can be designed flexibly and rectified facilely. For same frequency response, it can be realized preferably with the minimum number of IDT. The Firls optimization algorithm has the virtue that it can achieve precise linear phase.Copper phthalocyanine (CuPc) doped polyvinylpyrrolidone (PVP) thin film was deposited on the delayline of SAW sensor as a sensitive component, which was characterized by UV-vis absorption, IR spectra and X-ray photoelectron spectroscopy (XPS) techniques. The effects of mass variation, electric conductivity and temperature of deposited sensitive film on the central frequency of SAW sensor have theoretically been analyzed in detail. The relation between the shift of central frequency of SAW sensor and the mass variation of CuPc doped PVP film has been tested by electronic network analyses apparatus (ENA). The shift of central frequency of SAW sensor at different temperature, humidity and adsorbed gas has also been investigated. Using oscillating circuit, the property of SAW sensor has been tested. The results show that high frequency resonance SAW sensor is more sensitive than delayline type SAW sensor.