Function of Reference Impedance for Voltage and Current Sources
Specify the reference impedance to allow for the plotting of realised gain in POSTFEKO.
When the gain is calculated in Feko, it is calculated according to the IEEE definition where all losses are included, except for mismatch losses.
To view the realised gain in POSTFEKO with mismatch losses
            included, you need to specify the reference impedance.
    Note: Specifying the reference
                impedance does not affect the gain, source power or radiated power.