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Frequency domain simulation not converging

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Hi All,

I am currently working on a simulation of a coplanar stripline design. The striplines are considered perfect electrical conductors. I added a magnetic material that Lies along the coplanar stripline. I defined a dispersive permeability for this material following a drude-lorentz model dependence. The issue I am having is that when the damping coefficient is small (i.e permeability large), the simulation has trouble converging. Is there a way to work around this?

Best, Daniel Heligman


1 Reply Last Post May 19, 2021, 12:01 p.m. EDT
Robert Koslover Antennas, Waveguides, Electromagnetics

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Posted: 1 year ago May 19, 2021, 12:01 p.m. EDT
Updated: 1 year ago May 19, 2021, 12:09 p.m. EDT

Although I haven't worked with a drude-lorentz model, lack of convergence can arise for a variety of reasons in any Comsol model. What solver are you using? Is it direct or iterative? How good is your mesh quality (both average and worst-case)? Do you have a sufficiently fine mesh in volumes where field amplitudes or directions have strong gradients (likely to occur in/about your high permeability regions)? What discretization (linear, quadratic, cubic...) are you using? How does the convergence behave if you use a finer mesh? There are various options for launching and terminating waves, some of which are less problematic than others, so how are yours set up? Might any of your boundary conditions be improperly specified? You might want to post your model ( the .mph file) to the forum so others can look at it.

Although I haven't worked with a drude-lorentz model, lack of convergence can arise for a variety of reasons in any Comsol model. What solver are you using? Is it direct or iterative? How good is your mesh quality (both average and worst-case)? Do you have a sufficiently fine mesh in volumes where field amplitudes or directions have strong gradients (likely to occur in/about your high permeability regions)? What discretization (linear, quadratic, cubic...) are you using? How does the convergence behave if you use a finer mesh? There are various options for launching and terminating waves, some of which are less problematic than others, so how are yours set up? Might any of your boundary conditions be improperly specified? You might want to post your model ( the .mph file) to the forum so others can look at it.

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