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@Evan_Urban sir, I got the same error after union operation, I need the wire radius 0.6, then how can I fix this error
the ratio of wire radius to length is too large?
Altair EmployeeInstead of a wire, you can use a cylinder and then assign an Edgeport on it for excitation. That helps fix that thin wire error though you will have to mesh the cylindrical geometry. Please let me know if you have any more questions or need further clarification.
Respectfully,
Evan Urban
@Evan_Urban sir, I made the wire length long like -4 to 4mm , radius still 0.6mm, then there is no error, but I am getting S11 like this , may be because of the creeping waves in dielectric coated cylinder, do you think it is for port?
Hello,
Is your feed connecting from the inner radius of your structure to the outer? Can you provide your updated model so I can check everything for you? If there are no errors or warnings, then the results you see may be due to creeping waves, but I can check closer with your model.
Respectfully,
Evan Urban
I took a quick look at your model. I noticed your feed is extruding out of the cylinder (I do not believe this is what you desire(?)). This may be the reason as to why your S11 looks like it is. If you want your feed to touch both the inner and outer portions of the cylinder but keeping the radius 0.6, then you may want to follow constructing a cylinder with an edge port for the feed.
@Evan_Urban sir, I can't pick face in the cylinder to create edge port, can you kindly make the cylinder port in my model and attach here? Thanks!
@Evan_Urban sir thank you so much, now the result s11 is like this, I think I have to change probe location, cylinder radius to get good s11 bandwidth, now it confirms I think s11 has multiple resonances less than my simulated first case due to creeping waves. What do you think about this multi-resonance?
Considering the resonance, I cannot say much for the theoretical aspect, I apologize (may be due to creeping waves).
However, with the model I had provided you, Feko is giving accurate results. If you need to alter the position of the cylinder, keep in mind that both ends need to touch the PEC of the inner and outer full cylinder (May be good to separate the geometries and reunion after manipulations). Additionally, for the Edgeport, there has to be a small gap where the edgeport is placed within Freespace (There is a very small cylinder around the Edgeport in your model). With this in mind, you can maneuver the feed around to your desired position. Feel free to reach out if you are having issues regarding this.
@Evan_Urban sir thank you so much! sure if I need further assistance to move my probe, I will contact you again.
@Evan_Urban sir I am getting error, while I am trying to make variable feed_rad=0.65mm, just changing variable gives me this error
The reason for that is to define the Edgeport. To create an Edgeport you have to have the same media on both sides. So, in this case, I needed to create a small gap from the Edgeport to meet that criteria. I arbitrarily chose 0.05, you can change this as you want as long as it is there, but it is necessary to create the port.
@Evan_Urban sir thanks for the nice explanation!
I took a quick look at your model. I noticed your feed is extruding out of the cylinder (I do not believe this is what you desire(?)). This may be the reason as to why your S11 looks like it is. If you want your feed to touch both the inner and outer portions of the cylinder but keeping the radius 0.6, then you may want to follow constructing a cylinder with an edge port for the feed.
Sure, please give me some time and I will post a modified geometry for you.
Respectfully,
Evan Urban
Here is the modified file in 2023.1 version. I am looking forward to hearing your thoughts.
Considering the resonance, I cannot say much for the theoretical aspect, I apologize (may be due to creeping waves).
However, with the model I had provided you, Feko is giving accurate results. If you need to alter the position of the cylinder, keep in mind that both ends need to touch the PEC of the inner and outer full cylinder (May be good to separate the geometries and reunion after manipulations). Additionally, for the Edgeport, there has to be a small gap where the edgeport is placed within Freespace (There is a very small cylinder around the Edgeport in your model). With this in mind, you can maneuver the feed around to your desired position. Feel free to reach out if you are having issues regarding this.
That is interesting. I tried this on my end and did not get any error. But with this model I am receiving that error. I am looking into this in detail for you.
I changed the feed_rad back to 0.6 and ran the simulation, no errors appeared. I had rechanged the feed_rad back to 0.65, and now my simulation is running without an error. I am unsure why but I will look into reporting this as a bug in Feko.
The reason for that is to define the Edgeport. To create an Edgeport you have to have the same media on both sides. So, in this case, I needed to create a small gap from the Edgeport to meet that criteria. I arbitrarily chose 0.05, you can change this as you want as long as it is there, but it is necessary to create the port.
Hello,
It appears in your model you have two overlapping geometries, Unioning both your geometries together will solve this error.
After unioning I am getting another error the wire radius to length is too large. Thin wire approximation in Feko requires the radius of the wire to be 1/3 of the length of the wire. For example, if the length of your feed is lambda/10, your radius should be lambda/30. Not sure what radius you prefer in your simulation; I noticed for your mesh settings you have it set to 0.0000000001e-4 (Possibly mean 1e-4?), but locally on the wires you have 0.6. If you set the radius to 1e-4mm no errors are thrown.
I look forward to hearing back from you, hope this helps!
Respectfully,
Evan Urban