# Resonance Analysis

With version 6.0 the 3D Finite Element Method (FEM) has been introduced in the µWave Wizard as an additional method to solve Maxwell's equations. The 3D-FEM can also be used to calculate the resonance frequency of any structure. Typically the computation of the resonance frequency is important for designing of filters in particular for the layout of a combline filter.

The computation of the resonance frequency with µWave Wizard is done by using the 3D-FEM solver. A 3D-FEM mesh is generated for the circuit or element and the resonance frequency is computed for this circuit or for the elements. The circuit can contain any structure.

After selection of “Compute with 3D-FEM (x)” to a circuit or "3D-FEM" to an element and starting the "Project/Circuit resonance analysis" the resonance frequency will be calculated.

Material is ideal.

[Resonant frequencies of structure resonator_2_eigen]

+-------------+--------------------------+-------------------+

| mode number | Resonant frequency (GHz) | Unloaded Q-factor |

+-------------+--------------------------+-------------------+

| 1 | 2.112276 | oo |

+-------------+--------------------------+-------------------+

Material is copper.

[Resonant frequencies of structure resonator_2_eigen]

+-------------+--------------------------+-------------------+

| mode number | Resonant frequency (GHz) | Unloaded Q-factor |

+-------------+--------------------------+-------------------+

| 1 | 2.112013 | 7208.782 |

+-------------+--------------------------+-------------------+

It’s also possible to visualize the electro-magnetic fields of the resonant modes. This option is activated by the “Field plot parameter” for calculation on circuit level or the element properties “Field_comp=1”. By selection of this option the resonance analysis will additionally compute the electromagnetic field. The fields can be visualized by using the NTL3D viewer. For each resonance frequency the field can be visualized.