Measurment of mutual impedance of a dipole. Problem with results and derived data.

Hello,

I am using Comsol to model a dipole and a in a middle of permittivity 80 and conductivity 0. The model is a simple one and the study is in the frequency domain. The module used is AC/DC - Electric current. I am trying to determine the mutual impedance of the dipole. The electrodes are represented as terminals.

In the case of the dipole one of the electrodes is fed with a voltage of 1 volt the other electrode if fed with a voltage of -1 volt.

The theoretical formula used to calculate the impedance is :

Z = (V2 - V1)/i

Where "i" is the intensity fed to the electrodes, V1 is the potential at the center of the first electrode created by the second one and V2 is the potential at the center of the second electrode created by the first one

V1 0---------------------------<i>------------------------------0 V2

So in order to calculate the impedance value as a function of frequency I used the following formula in the Derived Values -> Global Evaluation :

(ec.V0_2-ec.V0_1)/rec(ec.Jx)

With V2 : ec.V0_2, V1 : ec.V0_1 and rec(ec.Jx) as i. "rec" is the integration of the surface of the receiving electrode and ec.Jx the current density on the x component.

Is my formulation in Comsol of the formula used to calculate the impedance correct ? It does not give me any errors but I am not sure of my formulation in Comsol.