18 Threads found on edaboard.com: Pml Boundary Cst
I was simulating using C*S*T software and I encounter a message saying
"inhomogenous material at pml boundary detected"
Could I know what does that mean and how about do I go about solving it?
RF, Microwave, Antennas and Optics :: 29.05.2004 07:20 :: yuppi77 :: Replies: 2 :: Views: 1209
I think you forgot to give the dimension of your pml vaccum box, so people cannot help much!
Just put your pml vaccum box at distance lambda/2 (minimum) from the closest microstrip.
It's a small box.
Electromagnetic Design and Simulation :: 12.08.2006 09:48 :: costox :: Replies: 9 :: Views: 1877
From my experience HFSS has more reliable and accurate eigenmode solver than cst (especially to calculate something lossy).
The fact that you need to specify lowest frequency in HFSS is a plus, because sometimes I need to find high order mode solution and it's not
possible to do it precisely with cst (you have to specify - 20-50 m
Electromagnetic Design and Simulation :: 19.02.2006 12:30 :: navuho :: Replies: 12 :: Views: 4361
Hi, everyone. I have some questions about the MWS-cst eigen solver for open-boudary case.
From the example of microstrip line eigen simulation sample in cst 2005, the top wall is assigned to PEC boundary instead of open boundary. I am wondering whether it is correct enough for higher-order modes?
Since in this case, (...)
Electromagnetic Design and Simulation :: 07.09.2006 13:06 :: jayleung :: Replies: 2 :: Views: 1392
Hi to all,
I want to get a dispersion diagram of a periodic structure where one side should be radiation boundary.How can I get that with cst or HFSS
by using the eigenmode solver that don't support,both, radiation(pml) or open add space boundary?
I should use an air box on the top. How sufficiently large and what should (...)
Electromagnetic Design and Simulation :: 14.10.2011 04:41 :: skymaster :: Replies: 0 :: Views: 708
both boundary condtions use pml (perfectly matched layer). The "add space" enlarges the calculation box automatically for antenna problems, i.e. radiation patterns.
RF, Microwave, Antennas and Optics :: 02.07.2006 17:10 :: Pushhead :: Replies: 8 :: Views: 2805
I am simulating a simple microstrip trace in cst. I am using discrete ports and pml (open + add space) boundary conditions. I notice that S12 does not quite reach 0dB at DC, even with PEC models for the conductors and no dielectric loss.
Is there something I should be doing to get S21 -> 0dB?
Electromagnetic Design and Simulation :: 11.11.2009 14:28 :: kowal_edward :: Replies: 1 :: Views: 1014
operates like free space – waves can pass this
boundary with minimal reflections. Perfectly matched layer (pml)
Open add space boundaries:
same as Open, but adds some extra space
for farfield calculation (automatically adapted to center frequency of
desired bandwidth). This option is recommended for an
Electromagnetic Design and Simulation :: 18.03.2010 04:12 :: eri :: Replies: 3 :: Views: 1292
in the help is:
Open (pml): Operates like free space: waves can pass this boundary with minimal reflections. Note that in case of a unit cell simulation with the general purpose frequency domain solver open boundaries are realized by a Floquet port.
Open (add space): Same as Open (pml), but adds some extra space for (...)
RF, Microwave, Antennas and Optics :: 15.03.2010 10:07 :: mauloftin :: Replies: 1 :: Views: 1684
I think simulating a semi-infinite substrate that is different from the background (eg vacuum) is trivial since cst automatically recognizes what you want to do. Just set up a finite thickness of the substrate beneath your structure, eg going down to Zmin. In the x and y direction use the unit cell boundary conditions and in z direction use the ope
Electromagnetic Design and Simulation :: 15.09.2011 06:54 :: goran1901 :: Replies: 5 :: Views: 1619
I am trying to simulate the propagation of of EM waves through the ground as well as the reflection from the surface. The main problem with the cad software that I used (HFSS, cst, Semcad) is the pml boundary conditions ? They seem to work only for a single background material and not for two half spaces (air/dielectric).
Electromagnetic Design and Simulation :: 12.12.2010 23:45 :: adel_48 :: Replies: 2 :: Views: 1496
As ColonelTigh mentioned: You can use any boundary (radiation or pml). If you use pml boundary, the results are more accurate compared to using the radiation boundary. Simulation takes a while longer if you use pml boundary.
Since you are using an array of 11 elements, (...)
RF, Microwave, Antennas and Optics :: 09.04.2011 17:55 :: sv1437 :: Replies: 6 :: Views: 928
How are you feeding your structure? Sometimes cst whinges (with cryptic, irrelevant errors) if the excitation ports are too close or touching the calculation boundaries. In particular, make sure your boundaries are set to "open" (i.e. pml) for antenna simulation. If you inadvertently have a "electric" boundary set, C
Electromagnetic Design and Simulation :: 26.11.2012 02:11 :: majidmad :: Replies: 5 :: Views: 800
I recommend you MicroStripes for antenna design. TLM time-domain tool (check my reply on HFSS size problem). No more pml crap or fancy boundary conditions needed. The only thing is there is no optimizer available yet but I heard the up-coming version 7 will have one. It really handles electrically large models, I would even
Electromagnetic Design and Simulation :: 06.12.2004 16:04 :: eirp :: Replies: 13 :: Views: 1930
I try to simulate the scattering field for a infinite extended dielectric plane using HFSS v.10.
I used a airbox with master/slave boundaries (side walls) & pml (top and botton walls) as boundary CONDITION and PLANE WAVE excitation.
See also attached hfss-file.
The results are not the ones expected. Does anybody have any idea of
Electromagnetic Design and Simulation :: 05.04.2006 14:51 :: flo2005 :: Replies: 4 :: Views: 2941
What about method of moments software?
Despite the fact that less people use them than FEM or FIT/FDTD they are extremely efficient in antenna simulation and don't suffer from any radiation boundary/ pml related problems. By efficient, I mean very fast and employing small amount of memory.
For instance, how much would it take to simulate accu
Electromagnetic Design and Simulation :: 22.05.2008 09:36 :: drasko :: Replies: 14 :: Views: 1445
I have a very tricky question for you today:
I need to simulate an antenna (loop) inside a pipe full of water. Obviously the antenna has been protected by a proper radome.
I need to know the farfield of the overall structure, but a problem occured.
Suppose that the plane of the loop is the yx and the pipe's axis is along z. Th
RF, Microwave, Antennas and Optics :: 01.03.2010 09:56 :: lsw17 :: Replies: 0 :: Views: 441
I define 2 wave ports (each port is far from structure face by 2*lambda) and the boundary is pml (far from structure face by lambda/4).
I don't think you should define ports far from the structure.
One port touch the front face of the structure, and the other port touch the back face.
RF, Microwave, Antennas and Optics :: 28.07.2011 18:00 :: tony_lth :: Replies: 3 :: Views: 393