Sato T, Abe H
Kinseki Ltd., Tokyo.
IEEE Trans Ultrason Ferroelectr Freq Control. 1998;45(2):394-408. doi: 10.1109/58.660150.
The dispersion properties of longitudinal leaky surface waves propagating under the periodic Al strip grating on lithium tetraborate (Li(2)B(4)O(7); LBO) are described theoretically and experimentally for applications of the mode to high frequency SAW devices. A theoretical method developed here is based on Floquet's theorem using space harmonics as an orthogonal function set and real boundary integral equations derived from the method of weighted residuals for a period of each region, i.e., substrate, metal, and free space. The boundary integral equations are solved by using the Galerkin procedure. The periodic strip gratings with both single-electrodes and double-electrodes are investigated, considering the convergency of the numerical computation for the number of the space harmonics. As a result, the propagation loss for shorted gratings was found to be relatively low in the thickness range of the Al strip below about 1% for the single-electrodes and 2% for the double-electrodes, although it greatly increases for a thickness over 2% for the single-electrodes and 3% for the double-electrodes.
针对纵向泄漏表面波在四硼酸锂（Li₂B₄O₇；LBO）上的周期性铝条光栅下传播的色散特性，进行了理论和实验描述，以将该模式应用于高频声表面波器件。这里开发的一种理论方法基于弗洛凯定理，使用空间谐波作为正交函数集，并从加权残差法为每个区域（即衬底、金属和自由空间）的一个周期推导实边界积分方程。通过伽辽金方法求解边界积分方程。考虑到空间谐波数量的数值计算收敛性，对具有单电极和双电极的周期性条形光栅进行了研究。结果发现，对于短路光栅，在铝条厚度范围低于约1%（单电极）和2%（双电极）时，传播损耗相对较低，尽管当厚度超过2%（单电极）和3%（双电极）时，传播损耗会大幅增加。
