Fundamental- and Harmonic-Frequency Circuit-Model Analysis of Lnterdigital Transducers with Arbitralry Metallization Ratios and Polarity Sequences
Fundamental- and Harmonic-Frequency Circuit-Model Analysis of Lnterdigital Transducers with Arbitralry Metallization Ratios and Polarity Sequences
复制标题
具有任意金属化比和极性序列的叉指换能器的基频和谐波频率电路模型分析
DOI：
10.1109/tmtt.1975.1128703
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发表时间：
1975
影响因子：
4.3
通讯作者：
W. Pedler
中科院分区：
文献类型：
--
作者：
W. R. Smith;W. Pedler
开发了一个三端口电路模型，该模型描述了具有任意金属化比率和电极极性序列的叉指换能器在基频和更高谐波频率下的操作。激发表面声波的电场是在逐个电极的基础上使用局部电场不受比下一个最近邻居更远的电极影响的近似值找到的。结果场用熟悉的函数表示，并在附录二中给出了一组“通用”展开系数。其他作者早期开发的电路模型中使用这些场，通过使用适合局部电极环境的膨胀系数对每个电极进行建模来描述任意换能器。说明性结果包括任意金属化比率的单电极和双电极换能器对于高达并包括十一次谐波的频率的有效耦合系数。还包括短换能器端部效应后果的一个示例，以及具有非交替极性序列的换能器[反相换能器（PRT）]的理论和实验的详细比较。
A three-port circuit model is developed that describes the operation of interdigital transducers with arbitrary metallization ratios and electrode-polarity sequences at fundamental and higher harmonic frequencies. The electric fields that excite surface acoustic waves are found on an electrode-by-electrode basis using the approximation that the local electric fields are not influenced by electrodes more distant than the next-nearest neighbors. The resultant fields are expressed in terms of familiar functions, with a "universal" set of expansion coefficients given in Appendix II. Use of these fields in the circuit model developed earlier by other authors describes arbitrary transducers by modeling each electrode using the expansion coefficients appropriate to the local electrode environment. Illustrative results include the effective coupling coefficient of single-and double-electrode transducers of arbitrary metallization ratio for frequencies up to and including the eleventh harmonic. Also included is one example of the consequences of end effects in short transducers, and a detailed comparison of theory and experiment for transducers with a nonalternating polarity sequence [phase-reversal transducers (PRT's)].