Problem with calculating the transmission line parameters in CST

[sameer1122]

I just want to calculate the transmission line parameters for a simple microstrip and compare with the theoretical values.
Using the theorectical equation (https://www.technick.net/public/code/cp_dpage.php?aiocp_dp=util_pcb_imp_microstrip) and the specifications
W = 1mm, h=1mm, T = .01mm, er = 4.4 , I am getting
Co=7.666085562280599e-11 and Lo = 3.9913806505935243e-7
============
I modeled the same in CST MWS2006 (model attached). But I am getting the tr line parameters as

Solver type = Transient analysis
Frequency = 0.05
Number of cascades = 100


C( 1, 1)
-----------------
1.446597e-013

L( 1, 1)
-----------------
3.486741e-011

R( 1, 1)
-----------------
0.000000e+000


G( 1, 1)
-----------------
1.773475e-007

Kindly help in identifying the mistake i made.[/quote]

 

[cplia]

Re: CST Help req

Discrepancies between CST and actual measurements can
be caused due to these common issues:
- Way you excite the structure. For microstrip line excitation use a plane
wave
- Meshing can be also crucial, examine your structure carefully
- Define material (dielectrics, metals etc.) properties in detail, considering losses etc.
- Boundary conditions, use same ones like the ones you use in your reference
design

MWS can easily handle such simple structures, like the one you try to simulate,
so it seems that your input parameters and your geometry need
to be re-examined.

Good luck!

 

[RFSimulator]

Re: CST Help req

Hi,

the online calculators return something line Inductance per meter.. e.g.

In MWS you get a pure Indutance value (NOT per meter).

Make sure that you transform one value to the other ...


Best regards,

F.