CAE Software【Femtet】Murata Software Co., Ltd.
The differential-mode and common-mode S-parameters are solved for a balanced line with connectors.
How to Reduce the Calculation Time
Item |
Settings |
Analysis Space |
3D |
Model unit |
mm |
Item |
Settings |
Solvers |
Electromagnetic Analysis [Hertz] |
Analysis Type |
Harmonic analysis |
Options |
Select “Ignore the influence of face/edge electrode thickness” * |
* This is the default setting. There are no face electrodes with this model. Therefore it is irrelevant to select it or not.
xx
Mesh tab, Harmonic analysis tab and Open boundary tab are set as follows.
Tab |
Setting Item |
Settings |
Mesh Tab |
Element type |
2nd-order element |
Multigrid/Adaptive Mesh Method |
Select “Use the adaptive mesh method”. |
|
Frequency-Dependent Meshing |
Reference frequency: 1×10^9[Hz] Select “The conductor bodies thicker than the skin depth constitute the boundary condition.” |
|
Harmonic analysis |
Frequency |
Minimum: 1×10^8[Hz] Maximum: 1.5×10^9[Hz] |
Sweep Type |
Select Linear step Division number: 10 |
|
Sweep Setting |
Select Discrete sweep |
|
Input |
1.0[W] |
|
Open boundary |
Type |
Absorbing boundary |
Order of Absorbing Boundary |
1st degree |
Two microstriplines are placed in parallel. They are connected to co-axial connectors.
The connectors are octagonal cylinders. Their end faces are set with the “I/O port” boundary condition. The integral path
is bridging the inner conductor and the outer perimeter.
Electric wall surrounds the model.
Body Number/Type |
Body Attribute Name |
Material Name |
1/Solid |
CONNECTOR |
Resin |
4/Solid |
CONNECTOR |
Resin |
5/Solid |
CONNECTOR |
Resin |
7/Solid |
CONNECTOR |
Resin |
15/Solid |
AIR |
000_Air(*) |
22/Solid |
METAL |
003_Ag * |
23/Solid |
METAL |
003_Ag * |
25/Solid |
METAL |
003_Ag * |
26/Solid |
METAL |
003_Ag * |
27/Solid |
METAL |
003_Ag * |
28/Solid |
METAL |
003_Ag * |
29/Solid |
SUBSTRATE |
006_Glass_epoxy * |
* Available from the Material DB
Resin’s property is as follows.
Material Name |
Permittivity |
Resin |
2.3 |
Boundary Condition Name/Topology |
Tab |
Boundary Condition Type |
Settings |
AUTO_PORT_1/Face |
Electric |
I/O Port |
50[Ω] |
AUTO_PORT_2/Face |
Electric |
I/O Port |
50[Ω] |
AUTO_PORT_3/Face |
Electric |
I/O Port |
50[Ω] |
AUTO_PORT_4/Face |
Electric |
I/O Port |
50[Ω] |
Outer Boundary Condition |
Electric |
Electric wall |
|
On the [Results] tab
click [Chart] and select SYZ Matrix.
On the SYZ matrix dialog box menu, click “Edit” and “Port Order Exchange/Balance Conversion”.
Select PORT1 and PORT2, and click the “Pair up” button. Then
select PORT3 and PORT4, and click the “Pair up” button.
You will see PORT(1,2)DIF, PORT(1,2)COM, PORT(3,4)DIF, PORT(3,4)COM in this order. You may change the listing order. For example,
select PORT(1,2)COM and PORT(3,4)DIF and press the “Exchange” button.
The S matrix will be listed as in the table below.
Table 1. S Matrix Listing Order and Abbreviation
Port Number |
Before Conversion |
After Conversion |
||
Title in Edit Dialog |
Title in Edit Dialog |
Note |
Abbreviatied Title |
|
1 |
AUTO_PORT_001:m1 |
DIFF(AUTO_PORT_001:m1,AUTO_PORT_002:m1) |
Differential mode of AUTO_PORT_001 and AUTO_PORT_002 |
1d |
2 |
AUTO_PORT_002:m1 |
DIFF(AUTO_PORT_003:m1,AUTO_PORT_004:m1) |
Differential mode of AUTO_PORT_003 and AUTO_PORT_004 |
2d |
3 |
AUTO_PORT_003:m1 |
COM(AUTO_PORT_001:m1,AUTO_PORT_002:m1) |
Common (same phase) mode of AUTO_PORT_001 and AUTO_PORT_002 |
1c |
4 |
AUTO_PORT_004:m1 |
COM(AUTO_PORT_003:m1,AUTO_PORT_004:m1) |
Common (same phase) mode of AUTO_PORT_003 and AUTO_PORT_004 |
2c |
In the SYZ Matrix dialog box, select “1 1”, “1 2” “1 3” and “1 4”, and press the [XY Graph]button.
The frequency plots of S parameters will appear.
See the table below for the S(x,x) notation.
Table 2. S Matrix Lookup Table
Title in Graph |
With Abbreviated Title |
S(1,1) |
S(1d,1d) |
S(1,2) |
S(1d,2d) |
S(1,3) |
S(1d,1c) |
S(1,4) |
S(1d,2c) |
1d,2d,1c and 2c are the abbreviated titles.