How to get simulated S-parameter of odd and even mode excitation for a coupled line coupler?
Hello,
First, I suggest reading the online help of the software. Specially look at the sections for assigning excitation for lumped and wave ports for either type pf solution. You can also try, (1) Choosing the driven terminal (not driven modal);(2) draw two terminal lines when setting the waveports; (3) after simulation, you can get the differential impedance Zdiff and common impedance Zcomm. Then the even mode impedance Zeven = 2*Zcomm, the odd mode impedance Zodd = 0.5*Zdiff.
Thanks,
In HFSS, you can directly obtain the modal responses and characteristics of a multiconductor transmission-line system by using wave ports in a driven modal simulation.
For your 3 conductor system, ensure each of your ports are exciting two modes; if everything is set up properly the first two will be the even and odd modes that you are looking for.
The scattering will be given in terms of each mode, as well as between them. So if you want the magnitude of the scattering of say, the first mode (typically the even mode), you would plot S(1:1,1:1), and S(2:1,1:1), where the first index is the port number, and the second is the mode number. So then if you wanted to plot the scattering response of the odd mode, you would plot S(1:2,1:2) and S(2:2,1:2). HFSS also solves other useful quantities of each mode such as Gamma (propagation constant) and Zo (characteristic impedance).
If you want to visualize the fields, you can set the weight of each mode under the menu HFSS->Fields->Edit Sources..
Dear Kumar,
I recommend you to reading the page No. 64 in the attached file "user’s guide – High Frequency Structure Simulator", because its very uesful for your question.
Regards
Stuart Barth
Thank you .....for your valuable comments.
I tried the steps for getting odd and even mode S-parameter but not getting the satisfactory result....may be there is some problem with port assignment.
I am trying to get the results of the paper attached. PFA
Smrity Dwivedi
Thank you mam...
I also tried method mentioned by you....but was unable to get the differential impedance Zdiff
Abhishek Kumar Does the paper you attached actually excite odd and even modes? It appears to excite four microstrip lines independently -- is this what you are doing?
Stuart Barth
In the attached paper, odd and even modes were excited and their respective odd mode S-parameters and even mode S-parameters were plotted in Figure 4.
I followed the steps suggested by you. I assigned wave port with 2 modes (one integration line from ground to one side of the feed line and other integration line from that feed line to the other feed line).
Here i have attached the screenshot of exciting mode and the graphs which i got after simulation.
Abhishek Kumar The authors in the paper don't seem to explicitly state that they directly excited these modes in such a fashion, but what you've done should work. Have you checked the field distributions of these modes to ensure they are correct? Something doesn't seem right about the low-frequency responses - while the authors get total transmission, as one would expect, you get strong reflection near DC.
Stuart Barth
I have corrected the convergence and then checked the field distribution for the modes..it looks ok.
Reflection near DC is now ok. Result for the odd mode S-parameter is fine but for the even mode its not ok.
Sir, which parameter need to be checked to know the odd/ even mode characteristic impedance (Z0(1:1),Z0(1:2),Z0(2:1),Z0(2:2)) ......
There are to option in result section (one is PortZ0 and other one is Z-parameter)
Can i get Bloch impedance in HFSS?
Here i have attached the results.....
- Badges
- Science topic
- Similar topics
- Computer Communications (Networks)
- Simulators