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piezoelectric resonator thickness shear mode

Posted Jul 23, 2014, 6:35 p.m. EDT MEMS & Nanotechnology, Piezoelectric Devices, MEMS & Piezoelectric Devices Version 4.3b 2 Replies

Farrukh Mateen
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I have a simple question about the thickness shear mode example tutorial provided with the MEMS model library in 4.3b. The resonator consists of a cylindrical piezoelectric material (Quartz) sandwiched between a positive terminal (top surface of the cylinder) and ground (bottom surface of the cylinder). If in the model the frequency domain analysis is run between 5.09MHZ and 5.13MHZ you get a good shear resonance, with terminal voltage of 10V. I have tried this and also if I increase the voltage to say 50 V I get the same resonance mode shape but higher amplitude which makes sense. ALso if I turn the terminal voltage to 0v there is no resonance at all. This is all perfectly intuitave.

But if I run an eigenfrequency analysis and ask for the first 50 eigenfrequencies then it doesnt matter whether the terminal voltage is set to 0v or 100v or 10v etc it will always give me the entire eignefrequencies along with the modes there amplitudes. SO my question is that shouldnt at 0v the eigenfrequencies should also be zero as in if the resonantor is still resonating at all those frequencies then whats the use of having the terminal voltage in the first place ???

Or is it that the software is reporting eigenfrequencies as the resonators own frequencies with which it will resonate when no external force or damping is applied.

2 Replies Last Post Jul 30, 2014, 10:29 a.m. EDT
Pieter Westerik
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Posted: 10 years ago Jul 28, 2014, 7:57 a.m. EDT
In eigenfrequency analysis, just the mode shape and the corresponding eigenfrequency is calculated. In a physical situation the amplitude will be proportional to the exciting voltage, but as long as no non-linear effects occur, the mode shape and corresponding resonance frequency will not change.
In eigenfrequency analysis, just the mode shape and the corresponding eigenfrequency is calculated. In a physical situation the amplitude will be proportional to the exciting voltage, but as long as no non-linear effects occur, the mode shape and corresponding resonance frequency will not change.
Farrukh Mateen
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Posted: 10 years ago Jul 30, 2014, 10:29 a.m. EDT
Thanks a lot this makes the situation pretty clear.
Thanks a lot this makes the situation pretty clear.

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