New Functionality inVersion 4.2

  • The Far field feature now supports far field in a medium other than vacuum. It has changed from being a boundary feature to being a domain feature with a (far field medium) domain selection and, as a sub feature, a boundary selection.
  • The Port feature now supports analytical circular ports in 2D axisymmetry.
  • It is now possible to compute S-parameters between ports and lumped ports and to include lumped ports in port sweeps and Touchstone export.

The following additions to the new functionality in COMSOL Multiphysics are of special interest for users of the RF Module:

  • Nyquist plots are available in 1D Plot Groups.
  • Logarithmic arrow length scaling is now provided for arrow plots.

Backward Compatibility vs. Version 4.0a

Overridden port variables removed from solution components

Overridden port features no longer generate solution components in version 4.1. Models built in version 4.0a and 4.0 with overridden port features will display an error message when opened in version 4.1. In order to successfully complete the import of such a model into version 4.1 you need to click OK to close the error message, then clear the existing solutions, and finally re-solve the model.

Java-files or M-files that create and solve COMSOL models containing overridden port features similarly need to be modified so that the code that generates the solver sequence does not refer to the removed solution components from the overridden ports.

Backward Compatibility vs. Version 3.5a

Change in Dependent Variables

Version 4.1 has a comprehensive set of electromagnetic wave propagation formulations based on the electric field that covers all modeling situations.

However, it is no longer possible to solve for the magnetic field H as a dependent variable.

Models saved in version 3.5a that are based on an H formulation are translated to the new E formulation but need to be solved again to update the solution in version 4.1.

Far-Field Postprocessing

Far fields are not automatically read in when importing a 3.5a model into version 4.1. The workaround is to manually add a Far Field Calculation node.

Pair Boundary Conditions

Pair boundary conditions are not yet implemented, except for some basic features. This means that the assembly port boundary condition is not supported in version 4.1.