摘要
　　本論文之研究目的，是以表面聲波(Surface Acoustic Wave)的傳遞機制來製作一表面聲波帶通濾波器(Surface Acoustic Wave Band-Pass Filter)，並利用變形及串並聯電路等動作來達成所需要的電路特性，再配合Mason等效電路方式來模擬壓電材料中表面聲波的頻率特性。學生參考表面聲波的原理，設計一系列之指叉狀電極轉換器(Interdigital Transducer，IDT)、輸延遲線(Delay Line)與反射閘(Reflector)的電路結構。
以本實驗為例，則是以上述設計兩種不同波長的表面聲波元件，分別為4.5μm及4.7μm，製作於48°Y-cut Lithium tantalite(鉭酸鋰，LiTaO3)壓電材料基板上，而產生兩種不同的頻率點，在有基礎的電路架構之後，再去進行變形及多階電路等動作，而達到中心頻率為890MHz且3dB頻寬約為25MHz，且預期能讓電路特性更好，並與市售的產品做比較。
藉由模擬軟體與下線結果做比較，發現模擬與量測之插入損失及通帶內有不理想特性產生，因此想從元件物理參數去著手找出不理想特性的原因，例如:金屬厚度、線寬線距比、反射閘與指叉電極周長比，並達到製程簡單化、體積縮小、成本降低等需求。

The purpose of this study is focused on the fabrication of Band-Pass Filter using the transmission mechanism of Surface Acoustic Wave. In order to achieve the characteristic of band-pass filter, we progress the simulation of the frequency properties using Mason Equivalent Circuit Model by the circuit simulation tool. In the implement of the SAW filter, we focused on designing architecture of SAW filter involved of interdigital transducer (IDT)、Delay Line、Reflector and piezoelectric materia1. In this paper, we design two kinds of wavelength on 48°Y-cut Lithium tantalitepiezoelectric materia1which represent the frequency of 860 and 890 MHz respectively. Under the condition that simple series-parallel connectioncircuit is realized, we go on deformation and multistage circuit for 890 MHz central frequency and 25MHz 3-dB bandwidth optimally on the basis of simple series-parallel connection circuit. The results werecompared with the commercial products. With the comparison of simulation and pattern out, there were several difference of frequency responses,such as insertion loss and resonate frequency. Therefore, we discuss the other possibility to make our design more simple、more compact and cost down.

[1] 朱慕道，“表面聲波元件原理與應用”，新電子—光電元件專輯，1994年3月，p183~p186.
[2] 王宏文, “淺談表面聲波感測器”, 工業材料—精密陶瓷專輯, 第 89 期 83 年 5 月, p44~p45.
[3] C. K. Campbell , “Surface Acoustic WaveDevicesfor Mobile and Wireless Communications”, 1997,p161~p168.
[4] C. K. Campbell , “Surface Acoustic WaveDevicesfor Mobile and Wireless Communications”, 1997,p395~p410.
[5] Fukuda T, Matsumura S, Hirano H, et al. Growth of LiTaO3 single crystal for SAW device applications[J]. Journal of Crystal Growth, 1979, 46(2): 179-184.
[6] OsamuYamazaki,TsuneoMitsuyuandKiyotaka,”ZnOThinFilmSAWDevices”IEEETrans.Sonic.andUltrason.Vol.SU-27,No.6,p.369-379,1980.
[7] C. K. Campbell , “Surface Acoustic WaveDevicesfor Mobile and Wireless Communications”, 1997,p31.
[8] LordRayleigh,“Onwavespropagatingalongtheplanesurfaceofanelasticsolid”,Proc.LondonMath.Soc.Vol.17,pp.4-11,1885.
[9] HerbertMatthews,“Surfacewavefilter”,JohnWiley&Sons.1977.
[10] J.J.CampbellandW.R.Jones,“Amethodforestimatingopitmalcrystalcutsandpropagationdirectionforexcitationofpiezoelectricsurfacewaves”,IEEETrans.onSonicsandUltrasonics,Vol.SU-15,pp.209,1968.
[11] C.S.Hartmann,D.T.Bell,Jr.andR.C.Rosenfeld,“ImpulseModelDesignofAcousticSurface-WaveFilters”,IEEETrans.onMicrowaveTheoryandTechniques,MTT-21,no.4,pp.162-175,1973
 
[12] C.K.Campbell,“SurfaceAcousticWaveDevicesforMobileand wireless and communications”，pp.79-81，1997.
[13] G.ACoquinandW.R.Jones,”Analysisoftheexcitationanddetectionofpiezoelectricsurfacewavesinquartzbymeansofsurfaceelectrodes,”J.Acoustic.Soc.Amer.,Vol.41,pp.921~939,1967.
[14] C.Dunnrowicz,F.SandyandT.Parker,“ReflectionofSurfaceWavesfromPeriodicDiscontinuities,”Proc.1997IEEEUltrasonicsSymp.,pp.386~390,1976.
[15] C. K. Campbell , “Surface Acoustic WaveDevicesfor Mobile and Wireless Communications”, 1997,p108~p112.
[16] C. K. Campbell , “Surface Acoustic WaveDevicesfor Mobile and Wireless Communications”, 1997,p159~p191.
[17] C. K. Campbell, Y. Ye and J. J. Sferrazza Papa,“Wide-band linear phase SAW filter design using slanted transducer fingers,” IEEE Trans. on Sonics and Ultrasonics, vol. SU-29, pp.224-228, July 1982.
[18] W. R. Smith, H. M. Gerard, J. H. Collins, T. M. Reeder, and H. J. Shaw, “Analysis of interdigital surface wave transducers by use of an equivalent circuit model”, IEEE Trans. MTT, Vol.MTT-17, pp856-864, Nov. 1969.
[19] W. R. Smith, H. M. Gerard, and W. R. Jones, “Analysis and Design of Dispersive Interdigital Surface Wave Transducers”, IEEE Trans. MTT, Vol.MTT-20, No.7, pp.458-471, 1972.
[20] W. R. Smith, “Experimental distinction between crossed-fieldand in-line three-port circuit models for interdigitaltransducers,”IEEE Trans. Microwave Theory and Techniques, vol. MTT-22, pp. 960-964, 1974.
[21] 吳良振, “表面聲波元件之設計研究”, 中原大學電子所碩士論文, 1999.
[22] 陳鉅棟, 陳秀貞, 莊添民, 黃銘鋒, “Design and Fabrication of Low-loss SAW Filters” HP EEsof 愛用者聯誼會, 第五屆年會論文集, 1996.
[23] Ou H H, Inose N, Sakamoto N. Improvement of ladder-type SAW filter characteristicsby reduction of inter-stage mismatching loss[C]//Ultrasonics Symposium, 1998. Proceedings., 1998 IEEE. IEEE, 1998, 1: 97-102.
[24] Namdeo A K, Nemade H B. Extraction of Electrical Equivalent Circuit of One Port SAW Resonator Using FEM-based Simulation[C]//Proc. of COMSOL Conference, Pune. 2015.
[25] Horine, B.H. And Malocha, D.C,, ”Equialent Circuit Parameter Extraction of SAW Resonators.” Proceedings of 1990 Ultrasonics Symposium, Vol.1, pp.477-482.
[26] Mark Vavin, Nancy Eisenhauer And Donald C.Malocha, “Parameter Extraction of SAW Resonator Equivalent Circuit Parameters And Package Parasitics.” IEEE Frequency Control Symposium, pp.384-390, 1992.
[27] 吳朗, “電子陶瓷—壓電陶瓷” pp.42-50, 1994.
[28] Shogo Inoue, Jun Tsutsumi, Takashi Matsuda, Masanori Ueda, Osamu Ikata, Yoshio Satoh,” Ultra-Steep Cut-Off Double Mode SAW Filter and Its Application to a PCS Duplexer” IEEE, September, 2007.
[29] Ueda M, Kawachi O, Hashimoto K, et al. Low loss ladder type SAW filter in the range of 300 to 400 MHz[C]//Ultrasonics Symposium, 1994. Proceedings., 1994 IEEE. IEEE, 1994, 1: 143-146.