Adding dielectric constant - Stackup Editor

[engr_joni_ee]

I have looked at the datasheets of dielectric materials. The dielectric constant values is a function of frequency. The value of dielectric is different at different frequencies. How can we add multiple dielectric constant values in the Stackup Editor of Xpeditation ?

 

[FvM]

How can we add multiple dielectric constant values in the Stackup Editor of Xpeditation ?

To achieve what?

Xpedition is using Er for impedance calculation, but it has no option to perform the analysis for different frequencies. Only a single value can be used. It's your job to select a representative Er value.

 

[engr_joni_ee]

Normally which value of the dielectric constant value we chose ? for example if we have a digital signal having clock frequency 600 MHz on the PCB then does it make sense to take the dielectric constant value at fifth harmonic frequency (3 GHz) which is considered to be the highest significant frequency content present in the signal.