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From material; use the conductivity specified by the material.
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Automatic (default in 3D); set the skin depth δs to be 100 times the geometry size and use that to deduce the appropriate conductivity σstab. The Typical frequency used for this conversion is taken from the solver. If there is no such frequency available — as is the case for a transient analysis — a Fallback frequency is used. The appropriate fallback frequency may differ per model and is best determined manually. Note that in addition to the fallback frequency, a solver-independent (user defined) frequency is an option too. A good value is the typical operating frequency of the modeled device. For more information, see Stabilization.
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From skin depth; very similar to the option Automatic, but with the added advantage that a user defined skin depth can be set.
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Off (default in 2D); disable the stabilization conductivity altogether: σstab = 0. This models a perfect vacuum and is a good approximation for air. In 2D oftentimes only the out-of-plane magnetic vector potential is used, providing sufficient stability.
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User defined; specify a suitable stabilization conductivity directly.
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Note that a Fallback frequency that is chosen too low may result in an overly damped model, just like a stabilization conductivity that is chosen too high, or a skin depth that is chosen too small. The device’s typical operating frequency, combined with a skin depth that is at least an order of magnitude larger than the device size, should provide a suitable stabilization conductivity.
When in doubt, it is recommended to check the amount of resistive loss in the insulators and compare this against the overall device loss. Sweeping over the stabilization conductivity (investigating the effect of different amounts of stabilization) or comparing against a Gauge Fixed model with zero stabilization is an option too.
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