Antenna Simulation : Folded Dipole #3061
Replies: 7 comments 9 replies
-
|
It looks from your diagram like you have a dipole source (red dot) on the left but not on the right, which should produce an asymmetric pattern? |
Beta Was this translation helpful? Give feedback.
-
|
Thank you for the hint. A "folded dipole" has only one feeding point. In theory and with dedicated antenna simulation software like "mmana-gal" (moment method) the "folded dipole" should have symmetric radiation pattern (beside minor asymmetry caused by the feeding cable. |
Beta Was this translation helpful? Give feedback.
-
|
What were the results with the simple dipole? Were they as expected? |
Beta Was this translation helpful? Give feedback.
-
|
Yes, the results with the simple dipole were as expected. With the folded dipole the simulation result is very sensitive to simulation parameters and looks like "chaotic" behaviour. |
Beta Was this translation helpful? Give feedback.
-
|
Have you tried radially increasing the number of mesh cells around your antenna? It looks like you only have 3 or so across the width of the antenna. I also can't tell if any cell boundaries fall directly on the boundaries. Increasing mesh count might help a lot. |
Beta Was this translation helpful? Give feedback.
-
|
Thank you for your hint. Now I tried to increase the mesh count. Sommetimes in the future, when I will have a pure linux computer available, I will try again to use meep with increased mesh count. |
Beta Was this translation helpful? Give feedback.
-
|
Can you send the model? I can give it a try.
…On Sat, Aug 2, 2025 at 2:49 AM HerbertDobernig ***@***.***> wrote:
Thank you for your hint.
Now I tried to increase the mesh count.
Unfortunately my ***@***.*** crashes all the time.
Windows OS seems to occupy 99% of the resources and the remaining 1% is
not sufficient.
Sommetimes in the future, when I will have a pure linux computer
available, I will try again to use meep with increased mesh count.
—
Reply to this email directly, view it on GitHub
<#3061 (reply in thread)>,
or unsubscribe
<https://github.com/notifications/unsubscribe-auth/AAB5E6XNQQ6STGW6UEJGNWT3LSCSPAVCNFSM6AAAAACBZY2FWKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGOJWHA2DMMA>
.
You are receiving this because you commented.Message ID:
***@***.***>
|
Beta Was this translation helpful? Give feedback.
-
|
In the meanwhile I
Simulation runs now more stable. |
Beta Was this translation helpful? Give feedback.
-
Beta Was this translation helpful? Give feedback.
-
|
https://github.com/NanoComp/meep/blob/master/python/examples/antenna-radiation.py |
Beta Was this translation helpful? Give feedback.
-
|
Is there example for solar cells? |
Beta Was this translation helpful? Give feedback.
-
|
idk |
Beta Was this translation helpful? Give feedback.
-
|
After experimenting with different dimensions (2D / 3D), resolutions, cell sizes, simulation walltime, ... Perhaps it would be possible with excessive simulation time or by using dissipative material around the antenna to somehow stabilize the simulation and to damp simulation oscillations. I attached the model that I used latest for your convenience, e.g. as starting point for similar investigations. 
|
Beta Was this translation helpful? Give feedback.
-
|
What is the blue line? Is that your nearfield/farfield conversion layer? Or
is it your PML?
In either case, shouldn't it be a bit further from the antenna?
…On Mon, Aug 4, 2025 at 5:16 AM HerbertDobernig ***@***.***> wrote:
After experimenting with different dimensions (2D / 3D), resolutions, cell
sizes, simulation walltime, ...
I was not able to get a fully symmetric radiation pattern out of the
simulation.
Perhaps it would be possible with excessive simulation time or by using
dissipative material around the antenna to somehow stabilize the simulation
and to damp simulation oscillations.
I attached the model that I used latest for your convenience, e.g. as
starting point for similar investigations.
Figure_5.setup.png (view on web)
<https://github.com/user-attachments/assets/fa004d6c-0f72-4098-98ad-4005c4976894> Figure_5_3D.radiation.pattern.png
(view on web)
<https://github.com/user-attachments/assets/0baad611-77ae-4599-9084-fca1a7f89353>
antenna.zip
<https://github.com/user-attachments/files/21577294/antenna.zip>
—
Reply to this email directly, view it on GitHub
<#3061 (comment)>,
or unsubscribe
<https://github.com/notifications/unsubscribe-auth/AAB5E6SPAHRCMUUES6H7HAD3L5FINAVCNFSM6AAAAACBZY2FWKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGOJYHAYTEOI>
.
You are receiving this because you commented.Message ID:
***@***.***>
|
Beta Was this translation helpful? Give feedback.
-
|
Yes, the blue line is the position of nearfield_box as well as the border to the absorber (or to a PML instead). Due to restricted computational ressources (memory), I am not able to use high resolution and large cell at the same time. (simulation breaks without meaningful error message, out of memory?) I tried both:
Up to now, I did not find restrictions like minimum distance from nearfield_box to antenna but I will revisit the documentation for further hints: (https://meep.readthedocs.io/en/latest/Python_Tutorials/Near_to_Far_Field_Spectra/) (https://meep.readthedocs.io/en/latest/Python_User_Interface/#near-to-far-field-spectra) |
Beta Was this translation helpful? Give feedback.
-
|
Use the tool that best fits. |
Beta Was this translation helpful? Give feedback.
Uh oh!
There was an error while loading. Please reload this page.
-
I started with the "antenna-radiation" example
I extended the model by adding an dipole antenna structure (two conducting staves) and got feasible radiation pattern results for different frequencies
I further extended the model by adding three conducting staves (one in parallel to the dipole and two short ones connecting on each end) thereby building a "folded dipole"
Problem:
In 2D as well as in 3D simulation the "folded dipole" shows fully asymmetric radiation pattern instead of the expected symmetric radiation pattern
Beta Was this translation helpful? Give feedback.
All reactions