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Knowledge Base

The Material Explorer is used to check the material fits that will be used in the simulation. This is most important when using the Sampled data material type, although it can be used to check material properties for all material types. If the fit for a Sampled data material is not good enough, the Tolerance and Max coefficient properties and the wavelength range of the source can be edited in the Material Explorer.

 

Plot window

The two figure windows at the top of the Material Explorer window show the real and imaginary parts of the material index.

Material settings

Property

Description

Material

Select the material to check.

Axis

If the material is anisotropic, select the axis to check.

Fit Tolerance

The Tolerance setting of the material. Only applies to fitted materials.

Max Coefficients

The Max coefficients setting of the material. Only applies to fitted materials.

Show/Hide Advanced

Show or hide the advanced options.

Imaginary weight

Increasing the weight increases the importance of the imaginary part of the permittivity when calculating a fit. A weight of 1 gives equal weight to the imaginary and real parts of the permittivity.

Make fit passive

Check to prevent the material fit from having gain at any frequency. By default this is checked in order to prevent diverging simulations.

Improve stability

Check to restrict the range of coefficients in the material fit in order to reduce numerical instabilities which cause simulations to diverge.

Specify fit range

Decouple the bandwidth used to generate the material fit and the source bandwidth.

Bandwidth range of fit

The frequency/wavelength range used for the fit if specify fit range is selected. The bandwidth of the fit should cover the simulation bandwidth.

Save fit parameters

Update the Material Database with the new Tolerance and Max coefficients values.

Simulation bandwidth settings

Property

Description

Bandwidth units

Specify range in units of wavelength or frequency. Specify range by Min/Max or Center/Span.

Bandwidth range

The frequency/wavelength range of interest. By default, this is the source limits.

Save source bandwidth

Update the source limits with these values.

View Settings

Property

Description

Vertical axis

Plot permittivity or index

Show material data

Show the experimental data on the plot windows

Standard view

Plot the fit over the specified bandwidth range

Extended view range

Plot the fit over a wider bandwidth range

Specify view range

Specify the range to plot the fit

Plot in new window

Plots fit and data in a new window

Fit and plot buttons

Property

Description

Plot in new window

Plot data in a new window

Fit and Plot

Calculate and plot the material fit

Fit analysis

Property

Description

Standard RMS error

The RMS error of the fit. The fitting algorithm will use the minimum number of coefficients required to achieve an RMS error less than the value specified by the Tolerance property of that material. If Imaginary Weight =1, then Standard RMS = Weighted RMS. If Imaginary Weight ≠ 1, then refer to the Weighted RMS error below.

Weighted RMS error

The weighted RMS error of the fit, calculated using the Imaginary Weight property of the material. The fitting algorithm will use the minimum number of coefficients required to achieve a weighted RMS error less than the value specified by the Tolerance property of the material.

Number of coefficients

The number of coefficients used in the fit.

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