Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
Simulating a resonant cavity
Posted 26.11.2016, 13:25 GMT-5 RF & Microwave Engineering, Studies & Solvers Version 5.2a 3 Replies
Please login with a confirmed email address before reporting spam
Hi
I want to simulate my tapered cone cavity to obtain a resonant frequency of that. I made a project but I can't compute that. There are some errors. I attach a project file.
I want to simulate my tapered cone cavity to obtain a resonant frequency of that. I made a project but I can't compute that. There are some errors. I attach a project file.
Attachments:
3 Replies Last Post 05.12.2016, 14:31 GMT-5
Please login with a confirmed email address before reporting spam
Posted:
8 years ago
Jakub,
There are several issues with your model:
1. You are trying to find resonant frequency for metal-filled cavity, which doesn't make much sense. Remove Copper domain material and add air domain material instead-this would give you air-filled cavity without losses.
2. Active port cannot be used in Eigenfrequency analysis -disable Port BC.
3. Increase Desired number of eigenfrequencies because several first modes might be spurious.
See attached file "Untitled_sy_no_losses.mph".
If you want to account for metal wall losses, then:
1. Add Copper material, change Geometric entity level to "Boundary" and select all exterior boundaries.
2. Apply Impedance Boundary Condition to all exterior boundaries of the cavity.
3. Impedance BC accounts for frequency-dependent losses and this makes eigenvalue problem nonlinear.
4. When solving nonlinear eigenvalue problem, it is necessary to provide initial guess for eigenfrequency and linearization point - you can do this under Eigenvalue Solver 1/Transform point.
See attached file "Untitled_sy_with_losses.mph".
Regards,
Sergei
There are several issues with your model:
1. You are trying to find resonant frequency for metal-filled cavity, which doesn't make much sense. Remove Copper domain material and add air domain material instead-this would give you air-filled cavity without losses.
2. Active port cannot be used in Eigenfrequency analysis -disable Port BC.
3. Increase Desired number of eigenfrequencies because several first modes might be spurious.
See attached file "Untitled_sy_no_losses.mph".
If you want to account for metal wall losses, then:
1. Add Copper material, change Geometric entity level to "Boundary" and select all exterior boundaries.
2. Apply Impedance Boundary Condition to all exterior boundaries of the cavity.
3. Impedance BC accounts for frequency-dependent losses and this makes eigenvalue problem nonlinear.
4. When solving nonlinear eigenvalue problem, it is necessary to provide initial guess for eigenfrequency and linearization point - you can do this under Eigenvalue Solver 1/Transform point.
See attached file "Untitled_sy_with_losses.mph".
Regards,
Sergei
Attachments:
Please login with a confirmed email address before reporting spam
Posted:
8 years ago
Thank you for reply.
Can you show me what I should do to simulate wall losses? Where are results? I don't know how to do that. Should I add at results at electric field a surface and set surface losses?
Where can I see which mode I am operating at each eigenfrequency and which mode is dominant?
Can you show me what I should do to simulate wall losses? Where are results? I don't know how to do that. Should I add at results at electric field a surface and set surface losses?
Where can I see which mode I am operating at each eigenfrequency and which mode is dominant?
Please login with a confirmed email address before reporting spam
Posted:
8 years ago
Hi
Can somebody tell me how can I obtain the operating mode? I try to do this, but I don't see there any options about that.
Can somebody tell me how can I obtain the operating mode? I try to do this, but I don't see there any options about that.