HFSS - Dispersion diagram of Sievenpiper's structure

dispersion diagram light line

Another thing, can someone tell me, from the dispersion diagram, which point is Gamma??

Thanks!

ebg dispersion diagrams

To the ones who are interested in using CST MWS for plotting dispersion diagrams.

You model your structure and assing periodic boundaries to them, and call them px and py, for instance. They got to be swept accordingly, to get the three areas of the Diagram.

What you do: make a parameter sweep first, from "gamma" to "X", where px is zero and py is swept from 0 to 180. The watch is gonna be "frequency of mode 1" etc. This is to be done under the Eigenmode Solver. After its done, keep the results under a folder (in 1D results right click and "add new tree folder"). Do another run for the "X to M" area, now you sweep px from 0 to 180 and let py equal to 180. Save the data and go to the last run, "M to gamma", where px and py are swept from 0 to 180.

In order to arrange all data in just one plot youll have to use the template post processing, if you are lazy like myself to export the ascii files to Matlab or alikes.
You call the plots (load 1D data file, external) on the template post processing. Call all three. Then the "X to M" needs to have a 180 shift on the x axis, use the option "1D result from 1D result" and write to these respective results x+180 under the option "x-scale function f(x)".

For the "M to gamma" it needs to be shifted and mirrored - instead of just x+180 you should write -x+540. Then its just a matter of copying and pasting the curves under some new created folder.

I think its all. Hope there aint mistakes....

plot dispersion diagram for ebg structure

hi mpero

well first of all thanks for your expanation of generating the dispersion diagram using CST MWS.
but i think its still not clear to me. this procedure which you mentioned has been discussed on this site before.
but the main problem is how to combine the three parts to get the complete dispersion diagram. you cant get the dispersion diagram for example for sievenpiper mushroom type structure if you use this method
i think if you have already generating this diagram using cst it would be great if you just upload ur model along with the results. many poeple will benefit from this

regards

dispersion diagram of ebg

Dear mpero,
Thanks for for explaining generating dispersion diagram in CST. I would appreciate if you upload the full model to let us see it in detail. Thank you.

Regards
Praful

brillouin zone dispersion diagram

I think it is a good way to do it
Thanks a lot!

sievenpiper

hi mpero

we are still waiting for you to upload the dispersion diagram of mushroom type EBG structure which you generated using CST


regards

hfss sievenpiper

mpre, thanks you very much for your guidance on dispersion diagram

close open boundary condition hfss

iT S very nice the post of mpre, i cheked and it worked, except the point : "...you should write -x+540"

I think you shoud try another relation of x cause it seems that not exact. Tks

dispersion diagrams -ieee article

Vey nice explanation for dispersion of OBG using CST. Can you tell me hw can we generate the Band map(Frequency vs r/a ratio plot) of PBG using CST????

hfss dispersion mushroom

Hello,

Can anybody upload(again) the CST and HFSS project files for the Sievenpiper's structure?

Thanks

kato01

Thank you all

Re: how to make dispersion diagram

RFgirl said:

Hi all,

Just came across this forum, and it definitely sounds heated up with respect to Sievenpiper's work and the dispersion diagram! I've found a dosument on ansoft's website that guides you to plot the 2D and 1D dispersion diagram (would like to share it here, except, am not too sure whether this is allowed, can somebody tell me if i can upload it here?)

Anyways, my main aim when plotting the 2D dispersion diagram is to find the eigenfrequencies of the high symmetry points (gamma, X and M). These values, along with the Bloch impedance will let me extract the inductance and capacitance values (LL, CL, LR, CR). My question is, does anyone have an idea about plotting the Bloch impedance? I've found a book on metamaterials that says that, the bloch impedance can be found by the formula ZB=2P/I*I, where P can be found from surface interation of E and H field of the port surface. This is in essence how the caracteristic impedance Zo is calculated on HFSS, using Zpi.

Does this mean I need to do the simulation in modal mode, and construct a port at the unit cell? If so, what's a good port size, since varying the port size will vary the terminal impedance. And, am i doing this correctly?? Please help!

Thanks alot!

Click to expand...

Hi RF girl,

Did u find a way to find the bloch impedance using HFSS. If so could you please advise me on this. I'm a bit confused with how to do integration in HFSS.

thanks