Power-insensitive silicon crystal-cut for amplitude-stable frequency synthesis
Power-insensitive silicon crystal-cut for amplitude-stable frequency synthesis
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用于稳幅频率合成的功率不敏感硅晶体切割
DOI：
10.1109/memsys.2017.7863343
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
R. Tabrizian
中科院分区：
文献类型：
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作者：
M. Ghatge;P. Karri;R. Tabrizian
本文报道了掺杂单晶硅(SCS)中存在功率不敏感晶体的理论预测和实验验证。这种截断的存在使伸展弹性波的完全简谐激励可以忽略不计的色散。将体声谐振器与这种功率不敏感的切割对齐，并抑制边界引起的非线性，可以实现对振动幅度不敏感的频率基准。给出了描述单轴弹性各向异性非简谐行为的解析公式，并预测了在偏离<；100>；轴30°的∼处存在功率不敏感截断。通过实现和表征一组排列成不同晶体方向的基于波导的谐振器，这一预测得到了实验验证。通过色散能量捕获技术，优化了谐振器，大大抑制了边界诱导的非线性。其中，与22.5°切割对齐的基于波导的谐振器在29dBm处显示出1分贝的压缩点，与<；100&>；/<；110>；对应的谐振器相比，其功率处理能力高出50倍。色散能量捕获用于消除几何非线性，同时在80 MHz处实现了∼7,000的高Q值，这与晶体的取向无关。
This paper reports on the theoretical prediction and experimental verification of the existence of a power-insensitive crystal cut in doped single crystal silicon (SCS). The existence of such a cut enables fully harmonic excitation of extensional elastic waves with negligible dispersion. Aligning bulk acoustic resonators to this power-insensitive cut along with suppression of boundary-induced nonlinearities enable realization of vibration-amplitude insensitive frequency references. An analytical formulation is presented to characterize the anisotropic anharmonic behavior of SCS elasticity, predicting the existence of the power-insensitive cut at ∼30° offset from <100> axis. This prediction is experimentally verified through implementation and characterization of an array of waveguide-based resonators aligned to different crystallographic directions. The resonators are optimized for substantial suppression of boundary induced nonlinearities through dispersive energy trapping technique. Among these, the waveguide-based resonator aligned to 22.5° cut shows a 1-dB compression point at 29dBm, which is 50× higher power-handling compared to <100> / <110> counterparts. Dispersive energy trapping used for elimination of geometrical nonlinearities simultaneously realizes a high Q of ∼7,000 at 80MHz, which is independent of the crystallographic orientation.