EM simulation of film capacitors
 

Hello everyone,
I'm trying to make an electromagnetic simulation of film capacitors, in order to extract the Impedance vs Frequency and Phase Angle vs Frequency curves, so also ESR vs Frequency. I started with Ansys Q3D; even with the simplest capacitor structure, that is parallel plate capacitor, the software doesn't seem to "understand" that I want to simulate a capacitor as a unique component, and not as two separated conductors. Maybe, this software needs a different way of setting this problem.
Does anyone have experience in the electromagnetic modeling of capacitors? Is there a better software to simulate Z vs frequency of these components?