Vasseur Clement, Croenne Charles, Vasseur Jerome O, Dubus Bertrand, Thi Mai Pham, Prevot Claude, Hladky-Hennion Anne-Christine
IEEE Trans Ultrason Ferroelectr Freq Control. 2018 Sep;65(9):1552-1562. doi: 10.1109/TUFFC.2018.2847246. Epub 2018 Jun 13.
A piezoelectric plate, poled along its thickness and supporting on its top and bottom surfaces a periodic grating of electrodes, is considered. An analytical model allowing band structure calculation is derived for the first symmetrical mode propagating along the length of the plate. Analytical results show that an electrical Bragg (EB) bandgap can be observed for this mode, depending on the electrical boundary conditions applied on the electrodes. This "EB bandgap" is associated with a discontinuity of the electric field between two successive unit cells. These results are validated with the numerical simulations based on the finite element method. Analytical and numerical results prove that the EB bandgap is highly tunable and can be optimized by changing the crystallographic orientation of the material. A simple tunable filter exploiting this bandgap is designed and fabricated. Experimental results of electrical impedance and electrical potential at the output together with a scanning laser vibrometer analysis are presented, which confirm the theoretical predictions.
考虑一块沿其厚度极化且在其顶面和底面支撑有周期性电极光栅的压电板。针对沿板的长度方向传播的第一对称模式，推导了一个允许进行能带结构计算的解析模型。分析结果表明，对于该模式，根据施加在电极上的电边界条件，可以观察到一个电布拉格（EB）带隙。这个“EB带隙”与两个连续单元之间电场的不连续性相关。这些结果通过基于有限元方法的数值模拟得到了验证。分析和数值结果证明，EB带隙具有高度可调性，并且可以通过改变材料的晶体取向来进行优化。设计并制作了一个利用该带隙的简单可调滤波器。给出了输出端的电阻抗和电势的实验结果以及扫描激光测振仪分析结果，这些结果证实了理论预测。
