Line impedance in CST

[emmagood]

Hi,

I am simulating a CPW structure in CST Microwave Studio. Its G/W/G is 75/90/75. When I connect two ports on the either ends and do a transient analysis, in the 2D results window --> Port --> Port 1, I cannot see the line impedance. (I need to be absolutely sure that my line impedance is 50 ohms). What could be the reason ?

I am using CST 2010 suite.

Any suggestions / ideas are gratefully welcome.

Thanks,

Emma Good

 

[emmagood]

also to add... I am getting hybrid modes and not Q TEM modes. is this going to have any effects on the line impedance not showing up...?

Thanks,

Emma.

 

[jianqiuzuo]

Hi Emma,

you cannot see the line impedance resulting from the hybrid mode. If it's not the TEM,
it means that we can not get the voltage and current, hence only wave impedance not line impedance.

you need to get rid of hybrid mode

 

[eoncu]

How to get rid of hybrid mode?Can anyone help about this point?Thanx in advance...

 

[johnjoe]

post a pic of your design

best regards

 

[thiadin]

hello. im new here. i have to design rectangular patch antenna by coaxial feed for 8 layers of LTCC. here is my specs.

ground and patch = copper annealed
patch =12.35mm x 16.14mm
ground and substrate= 24.7mm x 28.49mm
substrate = ferro A6S
inner/outer conductor = copper
radius inner conductor = 0.55mm
radius outer conductor = 2.0mm

i tried to design for the first layer of LTCC. there is no error and the simulation is done, but why my return loss graph look so weird? anyone can help me and check my simulation? this is my final year project.. tq..

 

[plasma]

I'm not sure but try it.
go to macro-> calculate -> transmission line

best regards