声表面波传感器Q值改善的理论与实验分析(英文)  

Theoretical and Experimental Analysis for Q Value Improvement of SAW Sensor

作　　者：杨莺[1] 朱大中[1] 

机构地区：[1]浙江大学信息与电子工程学系,杭州310027

出　　处：《传感技术学报》2006年第4期1083-1089,共7页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学与基金资助项目(60176027)

摘　　要：用P矩阵方法分析带变迹叉指换能器(IDT)和倾斜金属反射栅的高Q值Y型声表面波(SAW)质量沉积传感器的通带纹波,并分别在振荡和非振荡模式下比较了这些传感器的通带纹波和Q值。分析了获得高Q值的原因。理论和实验结果表明:均匀孔径无反射栅的传感器旁瓣抑制为10dB,振荡模式下其Q值为5289;通过孔径变迹设计,传感器的旁瓣抑制和Q值分别改善到25dB和8689;而对孔径变迹并加入倾斜反射栅的传感器,这两个参数提高到25dB和12477。非振荡模式下带反射栅的传感器比没有反射栅器件的通带纹波约低2dB。因此,变迹IDT和金属反射栅的应用是SAW质量传感器Q值的改善的两个重要因素。由于Q值改善,质量沉积灵敏度达到5.24GHz.A high Q Value Y type surface acoustic wave （SAW） mass sensor with apodized interdigital transducer （IDT） and slanting metal array reflectors is reported. P-matrix method was used to analyze the bandpass ripple of three different sensors. The Q value and bandpass ripple of these sensors were compared, respectively, in the active oscillation mode and non-oscillation mode. The reason for obtaining a high Q value was analyzed. Both theoretical and experimental results show that, the side lobe rejection of the sensor with uniformed aperture and no reflector is 10 dB and the Q value is 5 289 under oscillation mode; the side lobe rejection and the Q value are improved to 25 dB and 8 689, respectively by employing the apodization designing; however, both of these two parameters become 25 dB and 12 477, according to the application of the slanting metal array reflectors and the apodized IDT. In non-oscillation mode the bandpass ripple of the sensor with reflectors is about 2 dB lower than that of the sensor without reflectors. Therefore, the application of the apodization IDT and the metal reflector are two important factors to improve the Q value of the SAW mass sensor. Mass loading effect sensitivity is up to 5.24 GHz · cm^2/g, due to Q value improvement.

关 键 词：高Q值 声表面波 变迹 P矩阵 反射器 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TN65[自动化与计算机技术—控制科学与工程]