itchy00
Newbie level 4
Hi,
I'm trying to simulate a frequency selective surfaces in CST MWS.
I am using Frequency solver with floquet mode boundaries, meaning I choose unit cell for X,Y and open (add space) for Z.
Right now I'm only interested in transmission coeff. for zero incident angle, so I select only the first 2 floquet modes TE(0,0) and TM(0,0) for excitation (corresponding to a plane wave).
Now, my problem is the following.
When I simulate from 1 to 20 THz I get a different result than going from 1 to 10, then from 10 to 20 and then just putting the second graph at the end of the first.
I added a picture to show what I mean.
**broken link removed**
The top pictures are the single 1-10 and 10-20 measurements. The middle one is the combination of them.
The bottom picture shows the full 1-20 measurement, missing the two additional peaks at 8.5 and 9.5 THz.
Could anyone try to explain why this happens. And why only for 1 to 10 THz, because the 10-20 part looks pretty much the same in both calculations.
The results, in general, also seems to differ from the literature (see second attached picture).
**broken link removed**
Peak transmission frequency at 100% is the same, but where do the sidelobes (90% !!!) in CST come from? Due to the above problem I cannot really trust the CST calculations. Who tells me I chose the correct interval?!?!
By the way, the structure (for testing purpose) is a simple 33x33um square aperture in an infinitely thin 51x51um copper sheet. So not at all some kind of a "complicated" structure, but like the simplest case possible.
I hope anyone can help me. I'm almost sure I'm only doing a very basic mistake, assuming CST does not deliver incorrect results for such simple calculations
I'm trying to simulate a frequency selective surfaces in CST MWS.
I am using Frequency solver with floquet mode boundaries, meaning I choose unit cell for X,Y and open (add space) for Z.
Right now I'm only interested in transmission coeff. for zero incident angle, so I select only the first 2 floquet modes TE(0,0) and TM(0,0) for excitation (corresponding to a plane wave).
Now, my problem is the following.
When I simulate from 1 to 20 THz I get a different result than going from 1 to 10, then from 10 to 20 and then just putting the second graph at the end of the first.
I added a picture to show what I mean.
**broken link removed**
The top pictures are the single 1-10 and 10-20 measurements. The middle one is the combination of them.
The bottom picture shows the full 1-20 measurement, missing the two additional peaks at 8.5 and 9.5 THz.
Could anyone try to explain why this happens. And why only for 1 to 10 THz, because the 10-20 part looks pretty much the same in both calculations.
The results, in general, also seems to differ from the literature (see second attached picture).
**broken link removed**
Peak transmission frequency at 100% is the same, but where do the sidelobes (90% !!!) in CST come from? Due to the above problem I cannot really trust the CST calculations. Who tells me I chose the correct interval?!?!
By the way, the structure (for testing purpose) is a simple 33x33um square aperture in an infinitely thin 51x51um copper sheet. So not at all some kind of a "complicated" structure, but like the simplest case possible.
I hope anyone can help me. I'm almost sure I'm only doing a very basic mistake, assuming CST does not deliver incorrect results for such simple calculations