Technical Notes > The HFSS Solution Process > Solution Types           

Eigenmode Solutions

The Eigenmode solver can find the Eigenmodes of lossy as well as lossless structures, and can calculate the unloaded Q of a cavity. Q is the quality factor, and is a measure of how much energy is lost in the system. Unloaded Q is the energy lost due to lossy materials and boundary conditions. Because ports and other sources are restricted for eigenmode problems, the Q calculated does not include losses due to those sources.

The following restrictions apply to Eigenmode solution designs:

• No excitations may be defined.

• Radiation boundaries may not be defined.

• Frequency sweeps are not available.

• You may not view or plot the S-matrix data.

• Designs cannot include ferrite materials.

If a material or boundary condition, other than finite conductivity, varies with frequency, the eigenmode solution procedure will evaluate the frequency dependant property at the user specified minimum frequency and use that value during the S and T matrix assembly. This may limit the accuracy of the solved Eigenmodes depending on how significant the property varies from the minimum frequency to the eigen frequency.

Related Topics

Calculating the Resonant Frequency

Calculating the Quality Factor