增強MEMS諧振器的性能是設(shè)計MEMS諧振器的主要目標(biāo)。為了衡量諧振器的性能,可以用一系列的性能參來表征MEMS諧振器性能,包括諧振頻率、品質(zhì)因數(shù)、動態(tài)阻抗、非線性、功率容量和頻率穩(wěn)定性,這些參數(shù)可以用來衡量諧振器設(shè)計的好壞。這些參數(shù)中,高品質(zhì)因素是一個提高諧振器性能的關(guān)鍵參數(shù),并且在這些年的研究中被許多研究者提到過。錨點損耗是一種彈性波/聲學(xué)波通過支撐梁從諧振體傳導(dǎo)到基底產(chǎn)生的能量損耗。聲學(xué)波通過支撐梁的耗散會減小諧振器中存儲的能量,從而導(dǎo)致諧振器品質(zhì)因數(shù)的降低。因此,錨點損耗是設(shè)計MEMS諧振器時常見的關(guān)鍵參數(shù)。減小錨點損耗可以提高諧振器的品質(zhì)因數(shù),從而提升諧振器的性能。一些已知的可以用于減小錨點損耗并提高諧振器品質(zhì)因數(shù)（Q）的技術(shù)包括:支撐梁的優(yōu)化;利用諧振腔將振動的能量集中在諧振體中;利用聲子晶體將彈性波反射回諧振體并隔離諧振體與基底之間的彈性波/聲學(xué)波的傳播等。在這些技術(shù)中,聲子晶體（PnCs）結(jié)構(gòu)是一種廣泛應(yīng)用于減小MEMS諧振器錨點損耗的方法。利用一維（1D）聲子晶體和二維（2D）聲子晶體可以提供高的品質(zhì)因數(shù),但是一維聲子晶體會使器件對機械振動十分敏感。這篇論文提供了一個... 

【文章來源】：電子科技大學(xué)四川省 211工程院校 985工程院校 教育部直屬院校

【文章頁數(shù)】：104 頁

【學(xué)位級別】：碩士

【文章目錄】：
摘要
ABSTRACT
Chapter 1 Introduction
    1.1 Research Background and Significance
    1.2 State of Arts
    1.3 Contents and motivations of thesis
    1.4 Outline of thesis
Chapter 2 Theoretical basics
    2.1 Piezoelectricity Theory and Piezoelectric MEMS Resonators
        2.1.1 Piezoelectricity: early application and principles
        2.1.2 Piezoelectricity: mathematical expression
        2.1.3 Types of piezoelectric materials
    2.2 Resonator mechanical-electrical model and equivalent electrical parameter
        2.2.1 One-port resonator model
        2.2.2 Two-port resonator Model
    2.3 Phononic Crystals
        2.3.1 Introduction
        2.3.2 Crystallography arrangement
    2.4 Theory of phononic crystals
        2.4.1 Energy band structure, Bloch theorem, theory and mechanism of openingband gap
        2.4.2 Phononic Crystals categories
    2.5 Phononic Crystal application in MEMS based devices
        2.5.1 Phononic Crystals-based support tethers configuration
        2.5.2 Phononic Crystals -based resonators
        2.5.3 Phononic Crystals-based waveguide and filters
    2.6 Reflectors
Chapter 3 Thin-film piezoelectric-on-substrate technology and simulation tools
    3.1 Introduction
    3.2 Piezoelectric on Substrate
    3.3 Figure-of-merit of performance of MEMS resonators
        3.3.1 Quality Factor
        3.3.2 Power Handling
        3.3.3 Resonant frequency
        3.3.4 Motional resistance
        3.3.5 Nonlinearity
        3.3.6 Frequency stability
    3.4 Thin-film-piezoelectric-on-silicon based MEMS resonators
    3.5 Total Quality factor and Anchor Quality Factor
    3.6 Energy loss mechanisms in MEMS resonator
        3.6.1 Anchor loss
        3.6.2 Thermo-elastic loss
        3.6.3 Electrode loss
        3.6.4 Interface loss
        3.6.5 Material loss
        3.6.6 Air loss
    3.7 Band gap, dispersion curves and power transmission spectra in PnC
    3.8 analysis tools for acoustic wave propagation and MEMS devices
        3.8.1 Plane Wave Expansion method
        3.8.2 Finite-Difference Time-Domain method
        3.8.3 Simulation tool based on finite element method (FEM)
    3.9 COMSOL Multiphysics
        3.9.1 Eigenfrequency analysis
        3.9.2 Frequency domain analysis
        3.9.3 Parametric sweep
Chapter 4 Designing and Simulation Results of Cross-shaped PnC for anchor lossreduction of thin-film ALN-on-silicon high frequency MEMS resonator
    4.1 Introduction
    4.2 Thin-film ALN-on-silicon high frequency MEMS resonator design
    4.3 Summary of design parameters
    4.4 Simulation results and discussion
        4.4.1 Eigenmode shapes of the resonators
        4.4.2 Band gaps in cross-shaped PnC structure
        4.4.3 Band gab calculation
        4.4.4 Quality factor of the resonators
        4.4.5 Harmonic response of the resonator
    4.5 T-shape PnC with lattice constant a=20μm
    4.6 T-shaped PnC with lattice constant a=5μm
    4.7 T-shaped PnC with lattice constant a=10μm
    4.8 Applying T-shape PnC on the Resonator
    4.9 Harmonic response of the resonator
    4.10 Conclusion
Chapter 5 Conclusions
    5.1 Concluding Remarks
    5.2 Future work
Acknowledgements
References
Research Result Obtained During the Study for Master Degree



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