Comprehensive modeling of complex silicon microelectromechanical (MEMS) resonators
Abstract/Contents
- Abstract
- There is intense interest in micro and nanomechanical resonators for a variety of scientific and commercial applications. Microelectromechanical (MEMS) resonators are employed as frequency reference in various applications to generate an oscillatory signal from mechanical resonance. Dissipation of oscillation energy attenuates resonator's output signal. This attenuation is measured by the quality factor of the resonator. Therefore, high quality factor is a key factor for accurate measurement of frequency. Fundamental physical processes related to energy dissipation in MEMS resonators are not fully understood in general. For various resonators, different processes contribute to a different degree to the total energy dissipation. Due to interaction of mechanical vibration and energy dissipating processes, a strong coupling can take place leading to dissipation and a low quality factor. For simple geometries like a thin beam, quality factor can be reasonably predicted when resonating in the fundamental flexure mode but predictions deteriorate drastically as the designs get more complex to fulfill higher frequency and quality factor requirements. Dissipation in these resonators is generally complex and rarely well understood, and can be limited by quantum mechanical mechanisms. This thesis demonstrates exceptional modeling capability for a set of fundamentally different resonators. First, we provide a clear description of the relevant dissipation mechanisms and discuss models for accurate prediction of the quality factor. The essential difference of frequency reference technologies is set by resonator characteristics including frequency, quality factor and temperature sensitivity. We show by comparison to measurements of various devices built in our lab that we are able to predict performance for a wide range of resonators. As this level of agreement between modeling and measurement is generally unprecedented for arbitrarily complex devices, we hope it clarifies the relationship between the dissipation mechanisms and the probability of their appearance in different categories of resonators.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2014 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Ghaffari Jahromi, Shirin |
|---|---|
| Associated with | Stanford University, Department of Mechanical Engineering. |
| Primary advisor | Kenny, Thomas William |
| Thesis advisor | Kenny, Thomas William |
| Thesis advisor | Howe, Roger Thomas |
| Thesis advisor | Sheppard, S. (Sheri) |
| Advisor | Howe, Roger Thomas |
| Advisor | Sheppard, S. (Sheri) |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Shirin Ghaffari Jahromi. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2014. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2014 by Shirin Ghaffari Jahromi
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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