microwave absorber modeling in HFSS
i want to model an absorber(like AN75) in HFSS to eliminate the back radiation of a cavity back spiral antenna. how can i do this in HFSS.
in addition AN75 has a reflection curve like attached picture.
thank you in advance
that should be easy, just set materials u, u', etc. in the HFSS.
No need to get the performance.
hi tony.
i didn't understand.
i cant see material u or u' in hfss.
you mean i change the materials properties?
if you mean that what is the electrical properties of eccosorb like AN75?
Your question is too general to give a specific answer. What exactly are you looking for help with in HFSS?
hi.
i want to model an absorber in hfss in a specific frequency. (like 10GHz). for attenuate the back lobe of radiation of an antenna.
and i dont know the electrical properties of material like epsilon and mu and loss tangent.
So what do you need help with in HFSS?
Why is this a separate thread from this one? And why is this simulation question not in the simulation section of the forum?
It has been taken over by people who don't know how to ask questions properly.
i think there is a way in HFSS to attenuate a signal maybe with PML or something else.
my problem is attenuating signal in simulation. maybe with modeling an absorber in HFSS and put in the back of antenna or using a way to attenuate backlobe.
Yes, a PML will work as an absorber. So would a radiation boundary, or some other absorbing material. It depends what your specific requirements are. Are you trying to model a real life absorber, or will a PML be sufficient?
i just want to attenuate . not a real absorber.
if pml could do this it will be sufficient.
im designing a 2-18GHz spiral antenna with cavity back. i want to attenuate the backlobe in cavity.
how can i use the PML to eliminate the backlobe in cavity.
what is the PML setup for this problem.
Assign a PML on the surface where you want fields to be absorbed. Use the PML setup wizard, try the default values first and see if it works for you.
The two threads are now merged.
- moderator
hi. it didn't work. and the propagaion of wave did not changed with useing PML.
what is the u'?
i dont know!
U'?
What didn't work?
What do you mean the propagation didn't change? The wave would either be absorbed, in which case the PML is working perfectly, or it is reflected, in which case there is indeed a change.
Permeability. Usually u' is the real part, but in the context it was given i would assume imaginary part.
i used PML with default values in five side of a horn antenna. but i didn't see any major change in the propagated signal level in front of antenna. and the pattern have kept its shape and no change happened.
there is some question about PML setup.:
1: how far the pml should be placed away from antenna?
2: for operate as absorber which one should be set for "Base Face Radiation Properties"? "radiation only" or " incident field".
3: how much should be set for "Uniform Layer Thikness"?
4: how much loss should be happened for radiated field with PML?
Do you mean five sides, where you put a PML around every side of the antenna except the aperature? I'm not sure how this would be accomplished, can you show a picture?
At least 1/20 of a wavelength, the further the better though, depending on what you're trying to do.
Radiating only.
I usually use about 1/20 of a wavelength.
I'm not sure what you're trying to ask here. The reflection off of the PML should attenuated more than 20 dB of the incident.
a picture is attached.
thank you for your patience.
Hi J.C.Maxwell,
Why are you expecting that these PMLs will affect your radiation pattern? If you want to change the back lobe radiation pattern, your absorber needs to be attached to the antenna.