I want to design a lowpass microstrip filter (f0= 3-4GHz) with defined attenuation poles (3 poles at 6.6GHz, 8.3GHz and 10.2GHz). By doing this with PCB materials with frequency dependant dielectric constants I fail to meet all notches with one calculation.

Is there a way to define Er as a function of FREQ in the EQUATION-block?

Is there a way to define Er as a function of FREQ in the EQUATION-block?