Example9 Thickness Shear Mode

General

  • The thickness-shear mode vibration of AT-cut quartz is analyzed.
     

  • The frequency characteristics of electrode’s impedance and the displacement vectors are solved.
     

  • Unless specified in the list below, the default conditions will be applied.
     

 

Analysis Space

Item

Settings

Analysis Space

3D

Model unit

mm

 

Analysis Conditions

The analysis type is resonant analysis.

Item

Settings

Solvers

Piezoelectric Analysis [Rayleigh]

Analysis Type

Harmonic analysis

Options

N/A

The harmonic analysis tab is set up as follows.

Tab

Setting Item

Settings

Harmonic analysis

Frequency

Minimum: 18.0×10^6[Hz]

Maximum: 18.6×10^6[Hz]

Step

Select “Linear step by division number”.

Division number: 50

Model

Circular electrodes are placed on the top and bottom faces of the AT-cut quartz.

 

 

  • The quartz is divided into 3 layers in order to have properly sized meshes.
    The thickness of each triple layer is approximately 1/6 wavelength of the analysis frequency, which would yield the reasonable mesh size.

 

 

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

Quartz

301_Quartz *

3/Solid

Quartz

301_Quartz *

4/Solid

Quartz

301_Quartz

5/Sheet

Electrode

003_Ag *

6/Sheet

Electrode

003_Ag *

* Available from the Material DB

 

The cutting angle is set by Euler angle.

Body Attribute Name

Tab

Tab

Quartz

Direction

Specified by: Euler angle

Euler angle: Z=0, X=125.25, Z=0

Electrode

Thickness/Width

Thickness of Sheet Body: 0.2×10^-3

Boundary Conditions

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Settings

earth/Face

Electric

Electric wall

Voltage specified: Voltage 0[V]

hot/Face

Electric

Electric wall

Voltage specified: Voltage 1[V]

Results

The frequency plot of this antenna’s impedance is shown below.

The resonant frequency is around 18.32[MHz]. The anti-resonant frequency is around 18.36[MHz].

 

 

The thickness shear mode at 18.3[MHz] is calculated.

The displacement vectors for it are shown below.