Hi, matthew,
Thank you for your advice.

you said i need consider all mechanisms, and i know the total quality
factor  as

1/Qtot=1/Qviscousdamping+1/Qted＋1/Qother ,

i can deduce the 1/Qted, and can get the damping coefficient of the viscous
damping Cviscous, But how to combine these damping,   i'm not sure if i can
do this :

Qviscousdamping=m*Wn/Cviscous  , where Wn is the natural frequency of the
gyro and  the 1/Qtot can be obtained.

thank you in advance.



2008/10/27 matthew king 

> Mr Yan Xin,
>
>  I will try to answer your questions.
>
>  1 the damping of the system composed of  viscous
>  damping,thermoelastic damping and anchor losses,
>  but shall  i need  consider all the damping for the
>  damping coefficient in the motion equations or  just
> consider the viscous damping only?
>
> --Consider all mechanisms. But if you don't adopt
> vacuum packaging, the viscous damping will dominate.
>
>  2 how to calculate or deduce the viscous
>  damping(couette damping,squeeze
>  damping) of the device under the different pressure?
>
> --A lot of papers deal with that problem. Some
> examples are:
>
> Slide damping: Timo Veijola, et al, Compact damping
> models for laterally moving microstructures with gas
> rarefaction effects, JMEMS vol.10, No.2, 2001.
>
> Squeeze damping: Minhang Bao, et al, Squeeze film air
> damping in MEMS, Sensors and actuators A 136(2007)
> 3-27.
>
>
>
>  3  Does anyone knows a good paper to discuss the
>  deduction of the viscous damping?
>
> --- Refer to the answer above.
>