Perfect Magnetic Conductor and PML

hello,

PMC(perfect magnetic conductor) is an absolut isolator, right?

moreover, what is PML? i couldnt find it's defenition,

thank you

Magnetic: Operates like a perfect magnetic conductor, where the tangential components of magnetic fluxes and the normal components of electric fields are zero. This means that electric fields are parallel to the boundary and magnetic fluxes are normal to the boundary. For all magnetostatic or magnetoquasistatic applications magnetic boundary conditions correspond to normal boundary conditions. For all electrostatic or electroquasistatic applications they correspond to tangential boundary conditions. This boundary condition type is available for all EMS solvers.
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.

Well,

1. my question was: is the conductivity of pmc is 0? (as defined for hfss)
2. how do i define PML on a box in HFSS? and what do PML means? perefect magnetic what?

1) Since the PMC enforces that the tangential H-field is 0, there will be no electric currents on the surface, hence you can effectively say the electric conductivity is 0.

2) Perfectly Matched Layer. Select a surface, and then add a new boundary. Use the "PML Setup Wizard" at the bottom of the list.

Please let me know if this comment of mine is correct
No waves can pass through PMC.
Waves can pass through PML like free space with minimum distortion

nomigoraya said:

No waves can pass through PMC.

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I suppose, depending on what you call a "wave". The boundary condition does not support a normal component of the Poynting vector.

nomigoraya said:

Waves can pass through PML like free space with minimum distortion

Click to expand...

No. Propagating waves are highly attenuated inside a PML; this is how they "absorb".

PlanarMetamaterials said:

No. Propagating waves are highly attenuated inside a PML; this is how they "absorb".

Click to expand...

Sir I am using wakefield solver of CST and if I see help for open boundary it is as following
"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."
What this means ?

The CST documentation could be interpreted as correct, but its choice of wording seems very poor.

"Open" in the field of electrical/electromagnetics engineering usually refers to an open circuit, rather than the "absorbing", "radiation", or "emulation of free space" boundary that the PML is supposed to represent.

PMLs are designed for minimal reflection, when placed next to a free space object, they should "operate like free space" - i.e. an incident plane wave will pass directly into the boundary with no reflection. What the CST doc doesn't tell you is that once inside the PML, the wave is rapdily attenuated. They do not "pass through" the PML, rather they "pass into" the PML with minimal reflections.

The statement also tells you that in the simulation of periodic structures [implied, I believe, is that the structure is planar], a Floquet port should be used instead of a PML.

hello again,

Im using PML setup wizard,

i try to figure out what does Base Face Radiation Properties means ? ( you can pick Radiating only or incident field).

I built a structre (contains a loop and a wire) made of PEC which is illuminated by a planar wave. I've been told to use a box which covers my structre made of PML.

I tried them both.
It seems odd, when i picked Radiating only, it seems to block the incident wave, so no H or E field were found on my structure,
and when i chose incident field it seems to prevent returns from outside the structre, which means that all of the "energy" passed through the box into my object.

Do i get it right?

Another issue is why do i need to use that box at all? Even when i don't use it i get results (which are close to those i get when i pick incident field PML).

thank you

You can read more about PML settings in the HFSS help. Radiating is for free space radiation, incident field is for guided waves.

Your structure has PML boundaries on all sides? What are you trying to accomplish? If you aren't getting the correct behavior, try using radiation boundaries instead.

PlanarMetamaterials said:

You can read more about PML settings in the HFSS help. Radiating is for free space radiation, incident field is for guided waves.

Your structure has PML boundaries on all sides? What are you trying to accomplish? If you aren't getting the correct behavior, try using radiation boundaries instead.

Click to expand...

I read about PML settings in the hfss help, and then i asked here.
I built a PEC structre and i solve the scattered H field from a plane wave.
so i have 2 questions:

1. Should i close the structre with a box?
2. why should i pick incident field rather than radiation?
if i pick radiation i get H=0, and for incident field i get a correct result


thanks