声表面波谐振滤波器中纵横向耦合模式的研究及其复合应用

在通常的声表面波谐振滤波器中,由于采用的模式不同,纵向耦合谐振器具带宽大和插损低,带外抑制较差的特点;而横向耦合谐振器则具有带外抑制高,低插损及通带较窄的特点．为了综合两种滤波器的优点,采用了一种改进的滤波器结构,可同时利用纵向与横向耦合模式,得到既有较大带宽又有高带外抑制的声表面波谐振滤波器．运用耦合膜理论对纵横向模式的复合进行了分析,并在计算机上对这种结构的滤波器特性作了模拟,实验结果与模拟结果得到了较好的吻合．     

AIN/128°Y-X LiNbO_3层结构的声表面波特性研究

本文对A1N/128°Y-X LiNbO_3层结构的声表面波特性进行了研究。得到此层结构在较小的A1N膜厚时,不但具有延时温度系数(TCD)为零的特性;而且,在零TCD时,有高的机电耦合系数(k)及良好的频响特性。     

Combination of Loosely and Compactly Coupled Integrations of CAD Tools and Its Applications In SAW D

ＣｏｍｂｉｎａｔｉｏｎｏｆＬｏｏｓｅｌｙａｎｄＣｏｍｐａｃｔｌｙＣｏｕｐｌｅｄＩｎｔｅｇｒａｔｉｏｎｓｏｆＣＡＤＴｏｏｌｓａｎｄＩｔｓＡｐｐｌｉｃａｔｉｏｎｓＩｎＳＡＷＤｅｖｉｃｅｓＤｅｓｉｇｎａｎｄＦａｂｒｉｃａｔｉｏｎＰｅｉｇａｎｇＬｉ；Ｊｉａｑ...     

基于支持向量机的SAW传感器阵列鉴别毒害气体的研究

采用支持向量机技术, 对声表面波传感器阵列检测出的气体特征矢量和被测样本信息进行训练和分类, 鉴别出被测气体中的毒害气体. 实验结果验证了方案的可行性和有效性.      

基于声表面波谐振器的三维纳米团簇敏感薄膜关键技术研究

设计了一种新型基于声表面波技术的气体传感器,理论分析了三维纳米线结构的比表面积大、灵敏度高等优点,采用具备高Q值和低插损的谐振型声表面波器件结构,制备了三维敏感膜结构的声表面波气体传感器.在此基础上,为提高吸附效应,对三维纳米线簇进行了修饰改进.通过将沙林气和芥子气注入放置了声表面波的气体传感器密闭腔体内,经过神经网络识别系统进行定性识别.实验结果表明,基于修饰改进后的纳米线簇敏感膜制备的声表面波气体传感器对给定毒气混合气体的整理识别率大于90%,能够满足通用的毒气定性检测要求.并且三维纳米声表面波气敏传感器的灵敏度和响应速度优于传统的传感装置,在识别系统加大样本数据量时,能够进一步提高识别精度.     

基于DDC的SAW回波信号频率提取方法

SAW测量中,所要处理的回波信号具有瞬时、中频、窄带的特点,传统的FFT频谱分析法的频率分辨力受信号采样长度的制约,无法满足SAW测量的精度要求。基于SAW谐振器工作原理及信号特点,采用数字下变频技术降低回波信号频率,并以曲线拟合的方法提取信号频率;通过对比不同的谐振频率提取方法的处理结果,进一步验证了该方法的有效性。     

Propagation Characteristics of Surface Acoustic Waves on LGT and Quartz Substrates

Langatate （LGT） is a novel piezoelectric crystal; its structure is similar to quartz. A numerical analysis of the most important propagation characteristics of surface acoustic waves （ SAW） on LGT and quartz is presented in this paper. The results show that the phase velocity on LGT is slower than that on quartz. Similar to quartz. there are zero temperature cuts and pure module orientations on LGT. The electro-mechanical coupling constant （k2 ） of LGT is larger than that of quartz. The characteristics of SAW on LGT with different material constants are calculated and compared. The results show that there are somewhat deviations with different material constants. Especially. the temperature coefficient of frequency （ TCF） shows a relatively high difference.     

Si/Al/BN多层膜的制备及研究

本文采用磁控溅射系统制备了Si/Al/BN多层膜结构,并通过XRD,AFM,傅立叶红外光谱仪,纳米压痕仪等对Si/Al/BN多层膜结构进行了表征,表征结果表明本实验制备的Si/Al/BN多层膜基片符合高频声表面波器件基片的要求,为金刚石/IDT/BN多层膜超高频声表面波器件的制备奠定了基础.     

ZnO薄膜的制备及其特性研究

采用射频磁控溅射技术生长出高质量（002）晶面取向的ZnO薄膜.通过XRD和AFM研究了射频功率和氧气比例对ZnO薄膜的结构和表面形貌的影响.研究结果显示,射频功率在50W下氧气比例为45%时,所生长的ZnO薄膜可以用于制作高质量的表面声波仪（SAW）.     

Wavelet transform element of SAW type

This paper proposes to use substrate materials of small electromechanical coupling coefficient k^2 (such as X-112YLiTaO3) to manufacture wavelet transform element of SAW type so as to reduce finger reflections, i.e. to reduce the error of wavelet transform element of SAW type. And it is concluded that the smaller the center frequency of the transmitting IDT of wavelet type, the smaller the error. We suggest to choose substrate material with electromechanical coupling coefficient smaller than that of X-112Y LiTaO3 in the manufacture of the transmitting IDTs of wavelet type and the receiving IDTs at center frequencies above 100MHz, so as to reduce the errors of the transmitting IDTs of wavelet type and the receiving IDTs at center frequencies above 100MHz.