alienmindsinc
Newbie level 3
Good afternoon,
I'm trying to run a simulation of an infinite array of antennas, but I'm running into a problem. The requirement is to use Floquet ports, and as far as I can tell, I'm doing it correctly, but the results are all wrong.
I started off with a basic 25 mm square patch on 30 mm square dielectric with a height of 0.2 mm and no ground plane. According to the results, this was a perfect reflector. So I removed the dielectric, and got very similar results. Finally, I removed the patch, and again, same results.
Until this point, the air box was defined as follows: Floquet port on top with a axis on x, b axis on y. Master 1 with matching slave one on left and right, master 2 and slave 2 on front and back, no boundary on the bottom (it was the bottom of the dielectric).
The reason for this is that we are supposed to model the main array in Rx mode such that we can excite a plane wave away from the array and see how much of the energy reflects back. For this, I was told that S11 of the floquet port will be the reflection coefficient (meaning the amount of energy that returns to the port), and that S12 for the floquet port will be the transmission coefficient (meaning the amount that does not return/is absorbed by the array). Are these assumptions correct?
Anyway, after digging for a while, I found out that HFSS treats all surfaces as closed unless you specify otherwise, so for my last simulation, I used an empty air box bounded on the bottom with a radiation boundary, the top with a floquet port, and I left the sides in their original master/slave configuration. Once again, I'm getting confusing results from the S parameters.
I guess, I'm asking the following questions:
1. What am I doing wrong?
2. Is the model of an incoming plane wave bouncing off of a structure to supply the reflection coefficient a good way of thinking of the Floquet S parameters as everyone in the lab keeps telling me?
3. If I'm wrong, can you please explain what the Floquet port is doing?
I'm attaching my final empty cell so that you can see what I've done, and comment about it if it is wrong.
Thanks in advance.
I'm trying to run a simulation of an infinite array of antennas, but I'm running into a problem. The requirement is to use Floquet ports, and as far as I can tell, I'm doing it correctly, but the results are all wrong.
I started off with a basic 25 mm square patch on 30 mm square dielectric with a height of 0.2 mm and no ground plane. According to the results, this was a perfect reflector. So I removed the dielectric, and got very similar results. Finally, I removed the patch, and again, same results.
Until this point, the air box was defined as follows: Floquet port on top with a axis on x, b axis on y. Master 1 with matching slave one on left and right, master 2 and slave 2 on front and back, no boundary on the bottom (it was the bottom of the dielectric).
The reason for this is that we are supposed to model the main array in Rx mode such that we can excite a plane wave away from the array and see how much of the energy reflects back. For this, I was told that S11 of the floquet port will be the reflection coefficient (meaning the amount of energy that returns to the port), and that S12 for the floquet port will be the transmission coefficient (meaning the amount that does not return/is absorbed by the array). Are these assumptions correct?
Anyway, after digging for a while, I found out that HFSS treats all surfaces as closed unless you specify otherwise, so for my last simulation, I used an empty air box bounded on the bottom with a radiation boundary, the top with a floquet port, and I left the sides in their original master/slave configuration. Once again, I'm getting confusing results from the S parameters.
I guess, I'm asking the following questions:
1. What am I doing wrong?
2. Is the model of an incoming plane wave bouncing off of a structure to supply the reflection coefficient a good way of thinking of the Floquet S parameters as everyone in the lab keeps telling me?
3. If I'm wrong, can you please explain what the Floquet port is doing?
I'm attaching my final empty cell so that you can see what I've done, and comment about it if it is wrong.
Thanks in advance.