Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.
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.
Boundary conditions for Eigenfrequency analysis
Posted 18.02.2014, 11:15 GMT-5 RF & Microwave Engineering Version 4.3 0 Replies
Please login with a confirmed email address before reporting spam
Hi all,
I would be greatful if someone here could help me.
I am trying to simulate the resonance of a simple metallic dipole antenna
With a small gap in the middle for field concentration at THz freqs.
I am performing an eigenfrequency analysis with an initial guess at
2x the antenna length for the wavelength.
I am trying scattering boundary conditions applied to the outermost boundary of the air volume that surrounds the antenna.
For the Eigenfreq analysis I am inputting a linearization point of -i*2*pi*freq,
Where freq is the guess freq (as above).
The problem is as follows:
The eigenfrequency for the resonance I am interested in (dipole with
Field concentration in the middle) shifts in frequency depending on the
Extent of the air voulume in which I place it.
I have plotted the freq vs the air volume size (lets say it is a sphere but it also changes for other shapes) and there seems to be no saturation, aka I get a linear fit.
I would be greatful if someone could help me see what I am doing wrong in my analysis as I am unfamiliar with eigenfrequency analysis.
Regards,
David J
Hello David Jessop
Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.
If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.