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Resonance of a piezo device

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Hello,

I am working on verifying the mode shape of a piezoelectric resonator operating around 1GHz. By applying the appropriate boundary conditions and using the frequency domain study to sweep the frequency, I can almost exactly match the frequency found during lab experiments.

I have two questions, though.

I tried plotting the admittance, but it appears to be zero no matter what frequencies I sweep. However, if I plot the susceptance (the imaginary part of the admittance), I can clearly see the peak at resonance. Do you know why this might be?

Also, what I would like to do is verify the out-of-plane displacements at resonance. So, I try plotting a 1D line plot along the part I'm interested in. I should be getting something in the 200-300 picometer range, but what I get is a line the wiggles and loops in a way that is physically impossible. Is there anything you can tell me about how COMSOL calculates mode shapes, or displacements - is it possible the a round off error is happening somewhere, or is there a bug somewhere? I've tried everything to fix it.

Thanks,
Kamala

1 Reply Last Post 7 déc. 2011, 20:02 UTC−5
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Hello Kamala McNaul

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Posted: 1 decade ago 7 déc. 2011, 20:02 UTC−5
Hi Kamala,

If you do not turn on the damping of the piezoelectric resonator, the conductance (real part of the admittance) is always zero.

Best
Ye
Hi Kamala, If you do not turn on the damping of the piezoelectric resonator, the conductance (real part of the admittance) is always zero. Best Ye

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