CAE Software【Femtet】Murata Software Co., Ltd.
Example11 Magnetic Field Distribution of Coil Antenna with Capacitor for Resonance
General
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Magnetic field distribution at the LF band (around 130KHz) is analyzed.
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The magnetic flux density distribution, the circuit current, and the inductance are calculated.
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The analysis is coupled with the external circuit.
Resonant capacitors are placed in the external circuit. -
Unless specified in the list below, the default conditions will be applied.
Analysis Space
|
Item |
Setting |
|
Analysis Space |
3D |
|
Model Unit |
mm |
Show Results
|
Item |
Setting |
|
Solver |
Magnetic Analysis [Luvens] |
|
Analysis Type |
Transient Analysis |
|
Options |
Select [Inductance Calculation]. |
The Transient Analysis tab is set up as follows.
50KHz AC is input. To reproduce its waveform well, the timestep is set by dividing the periodic time of 50KHz by 12.
|
Tab |
Setting Item |
Setting |
|||||||
|
Transient Analysis |
Timestep |
Automatic |
|||||||
|
Table |
|
External circuit is as follows.
An AC power is placed on the primary side.
The primary coil and the secondary coil are connected on the model side.
The capacitors are connected to both of the primary and secondary coils in order to have the LC series resonance.
Model
The primary coil (Coil1) and the secondary coil (Coil2) are defined by the loop coil.
Body Attributes and Materials
|
Body Number/Type |
Body Attribute Name |
Material Name |
|
5/Solid |
Coil1 |
008_Cu * |
|
4/Solid |
Coil2 |
008_Cu * |
* Available from the material DB
The body attribute is set up as follows.
Each coil is linked to the FEM coil on the external circuit.
|
Body Attribute Name |
Tab |
Setting |
|
Coil1 |
Current |
Waveform: External circuit coupling Coil name on the circuit: FEM_Coil_1 Turns: 100[Turns] Direction: Loop Coil/Magnetic Field Direction Direction Vector of Magnetic Field: X=0, Y=0, Z=1 |
|
Coil2 |
Current |
Waveform: External circuit coupling Coil name on the circuit: FEM_Coil_2 Turns: 100[Turns] Direction: Loop Coil/Magnetic Field Direction Direction Vector of Magnetic Field: X=0, Y=0, Z=1 |
Boundary Condition
No setting.
Results
The distribution of the magnetic flux density at 0.25641e-5[s] is shown below.
The circuit current waveforms are as follows.
The current of the primary coil (blue wave) is a sine wave and shifted from the voltage power (cosine wave) by π/2 phase.
The currents of the primary coil and the secondary coil show the opposite phases.
The result of inductance calculation is shown below.
Self inductance [H] Mutual inductance [H]