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FBAR model

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Hi,
I'm trying to build a simple model of a Thin film bulk acoustic wave resonator. I followed an example and built one myself. However, my own model somehow gave a different result (impedance) from the example which I could not figure out why.
This is the example model
mega.co.nz/#!NohEjJhQ!aZOcDSYvL4pof__tYallazWXM8Y9LWbuOTn8pl_8Qz8
and my own one
mega.co.nz/#!wsoHEYxY!Dx8YoWK2x3hMs8n7OklIeR4XDbMW4jjgVBPzXDD4mAQ

Can anyone please help me with this?
Regards,
Ngoc

2 Replies Last Post 7 ott 2013, 08:57 GMT-4
Bertil Nistad COMSOL Employee

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Posted: 1 decade ago 7 ott 2013, 02:57 GMT-4
Hi,
The difference is that in your model, you've included the mechancial and electrical losses in the electrodes. This is not included in the example model and will for sure alter the admittance of the resonator.

Best regards
Bertil Nistad
COMSOL
Hi, The difference is that in your model, you've included the mechancial and electrical losses in the electrodes. This is not included in the example model and will for sure alter the admittance of the resonator. Best regards Bertil Nistad COMSOL

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Posted: 1 decade ago 7 ott 2013, 08:57 GMT-4
Hi, Bertil

Thank you for answering me. I tried modifying the isotropic structural loss of the electrode in the example model to the same value as in my model, but the result seems to be unchanged. I found some websites, and they said something about the piezoelectric material plane which can cause the unexpected low impedance in my model. However, I didn't see any difference in material plane between two models. Is there any chance that I missed something when checking this?

Regards,
Ngoc
<Newbie in COMSOL>
Hi, Bertil Thank you for answering me. I tried modifying the isotropic structural loss of the electrode in the example model to the same value as in my model, but the result seems to be unchanged. I found some websites, and they said something about the piezoelectric material plane which can cause the unexpected low impedance in my model. However, I didn't see any difference in material plane between two models. Is there any chance that I missed something when checking this? Regards, Ngoc

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