矽基二維聲子晶體之全頻溝量測及應用

Measurement and applications of total band gap with Si-based phononic crystals

鄭宗誠(Tsung-Cheng Cheng)

指導教授 ： 吳政忠

國立臺灣大學/工學院/應用力學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.02503

摘要

無資料

關鍵字

表面聲波 ； 斜交指叉換能器 ； 層狀表面聲波元件 ； 聲子晶體 ； 全頻溝

並列摘要

During the past two decades, there has been a great deal of interest in studying a novel class of structures that are the phononic crystals. In this kind structure, the special character, that is the band gap phenomenon, prohibiting acoustic waves of specific frequencies from traveling through the crystals. Recently, the band gap along x direction has been measured in the micro-scale 2-D air/silicon phononic crystal. However, another character, the so-called total band gap, forbids acoustic wave along any directions. The location of total band gap will be measured by wide-band surface acoustic wave (SAW) filter in this study. In order to predict the total band gap width of surface waves of micro-scale phononic crystals, the plane wave expansion (PWE) has been used to simulate the dispersion relation of 2-D air/silicon phononic crystals.
In general, the slanted finger interdigital transducer (SFIT) is utilized as the wide-band filter. Since silicon is not a piezoelectric material, we need another layer of piezoelectric material to excite surface acoustic wave and the layered structure SFIT/ZnO/Silicon is chosen in this study. For the layered structure, the dispersive relation is calculated by the effective permittivity approach, and the frequency response can be simulated by the coupling-of-modes (COM) model. Because the actual parameters of a layered SFIT are different slightly from the designed parameters, the simulated frequency response must be modified. The results demonstrating the modified simulations are in good agreement with experimental frequency response.
Finally, the lower limit of first total band gap and frequency range of 2-D air/silicon phononic crystals in micro-scale are successfully measured by the layered SFIT.

並列關鍵字

SAW ； SFIT ； layered SFIT ； phononic crystals ； total band gap

參考文獻

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