I.H.P.SAW谐振器孔径对性能的影响

该文研究了在超高性能声表面波(I.H.P. SAW)衬底上，孔径总长对叉指末端具有能够抑制横向模态的小锤结构的谐振器性能。在衬底结构为Y 42°-钽酸锂(Y42°-LT)/SiO₂/多晶硅(Poly-Si)/Si上，通过建立对应的有限元三维仿真模型，初步得出在小锤结构下孔径总长的增大能够抑制横向模态杂散的结论。绘制了周期T为1.44μm、2μm、2.56μm下，孔径总长为7.5T、10T、15T、20T、25T、32.5T、40T的单端口谐振器版图并进行流片。通过实测结果表明，在不同周期下，随着孔径总长的不断增加，对谐振器横向模态的抑制会不断增强，机电耦合系数也不断增加，在孔径总长约为20T时阻抗比最高。仿真和实测结果体现了孔径总长对I.H.P. SAW谐振器的性能影响较大，为应用于I.H.P. SAW滤波器中的高性能谐振器提供了设计指导。

Influence of Aperture of I.H.P. SAW Resonator on Performance

In this paper, the resonator performance of a small hammer structure with the interdigital end of the total aperture length on an Incredible High-performance surface acoustic wave (I.H.P. SAW) substrate is researched. On the substrate structure of Y42°-lithium tantalate (Y42°-LT)/SiO₂/polysilicon (Poly-Si)/Si, the corresponding 3D finite element simulation model was established. It was preliminarily concluded that the increase of the total aperture length with the hammer structure can suppress the stray in the transverse modes. The layouts of a single port resonator with a total aperture length of 7.5, 10, 15, 20, 25, 32.5, and 40 times of the period at 1.44, 2, and 2.56 m periods are drawn and taped out. According to the measured results, it is concluded that with the continuous increase of the total aperture length in different periods, the suppression of the transverse mode of the resonator will continue to increase, the electromechanical coupling coefficient will also continue to increase, and the impedance ratio is the highest near the period with a total aperture length of 20 times. The above simulation and measurement results show that the total aperture length has a great influence on the performance of I.H.P. SAW resonator, which provides design guidance for high-performance resonators used in I.H.P. SAW filters.