HFSS Radiation Boundary Question
时间：03-31
整理：3721RD
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I have a question about how HFSS handles a radiation boundary when one of the boundary edges touches a pec conductor.
The structure I am looking at is a very long open-ended waveguide (assume no wall thickness for simplicity). I enclose the open-end waveguide in a large radiation box and the port-excited end is outside of the box. The length of waveguide inside the box is variable, say L. One of the RBC faces of the radiation box has a radiation boundary condition that has four edges which touch the sides of the (conducting) waveguide walls. It seems that the resulting radiation pattern depends on the length L. In other words, there does seem to be reflection from the radiation boundary condition where it touches the waveguide walls. Although I have not verified thoroughly yet, the pattern seems to be fairly close to a finite-length (length L) open-ended waveguide.
I was always under the impression there would be no reflection from an RBC, but does that only apply when the surface does not touch anything else? It seems, that when it is adjacent to a conductor, the pattern includes the diffraction effects as if the the conductor is truncated sharply at the radiation boundary.
Is there anyone who can explain this more fully? How are we supposed to view the actual model being analyzed in this case? Is there anyway to be able to use a finite radiation box to model a semi-infinite, open-ended waveguide? Thanks for your help.
John.
The structure I am looking at is a very long open-ended waveguide (assume no wall thickness for simplicity). I enclose the open-end waveguide in a large radiation box and the port-excited end is outside of the box. The length of waveguide inside the box is variable, say L. One of the RBC faces of the radiation box has a radiation boundary condition that has four edges which touch the sides of the (conducting) waveguide walls. It seems that the resulting radiation pattern depends on the length L. In other words, there does seem to be reflection from the radiation boundary condition where it touches the waveguide walls. Although I have not verified thoroughly yet, the pattern seems to be fairly close to a finite-length (length L) open-ended waveguide.
I was always under the impression there would be no reflection from an RBC, but does that only apply when the surface does not touch anything else? It seems, that when it is adjacent to a conductor, the pattern includes the diffraction effects as if the the conductor is truncated sharply at the radiation boundary.
Is there anyone who can explain this more fully? How are we supposed to view the actual model being analyzed in this case? Is there anyway to be able to use a finite radiation box to model a semi-infinite, open-ended waveguide? Thanks for your help.
John.
Hi everyone
I want to simulate a slotted equiangular spiral antenna for my research project in MSc could someone help me to draw this in hfss and simulate
Email : supem1981@gmail.com
Thank you
Added after 21 seconds:
Hi everyone
I want to simulate a slotted equiangular spiral antenna for my research project in MSc could someone help me to draw this in hfss and simulate
Email : supem1981@gmail.com
Thank you
i think if u r studying some radiation from open ended waveguide u should put radiation box at least lamda/4 from each edge so that proper study can be done
u can attach your file..i can see that
What about the problem of not too much radiated? Is lamda/10 OK?