Inconsistent results between Terminal Wave Port and Terminal Lumped Port when simulating a flat FCC cable ... can someone help me ?

[rdpdo2002]

Hello,

I would like to simulate the system {connector1 + 24 inches cable + connector2}, something like this :

Obviously, I cannot simulate this because of the computing cost....


But under HFSS, I can use deembedinbg using wave ports (but not using lumped ports) so my idea is to simulate :
- the S-parameters of the connector1 inputs / output
- a little length of cable using wave ports
- dembed to get the 24 inches lenght of cable
- the S-parameters of the connector2 inputs / output (which are the same as connector1)
- Add all the circuits in series

I am just wondering if I can add the S-parameters circuits in series and if it is correct to add them to get the total system s-parameters ?

Thanks you for your advice

 

[D.A.(Tony)Stewart]

is PET Er= 3.4 ?

--- Updated Nov 5, 2024 ---

Just verify Zo

 

[rdpdo2002]

is PET Er= 3.4 ?

--- Updated Nov 5, 2024 ---

Just verify Zo

I use 3.59861 :

 

[rdpdo2002]

I haven't yet taken the time to take my measurements on my cable but Molex sent me a measurement report of the S-parameters : As you can see, they connect the GND Aluminium shield to the GND between differential signals... I'm going to have to do some welding, it's bothering me... Do you think this has an impact on the characteristic impedance value to connect the SHIELD Aluminium plane to GND or not ?

Another thing that bother me is that they don't want to give me the s-parameters files son I cannot get the temporal S11 to calculate the caracteristic impedance along the line...

I will try to make simulation using Aluminium SHIELD as supplementary plane GND and see if I can obtain results consistant with molex's results.

​