Help on calculating port impedance Zpv using Field calculator under HFSS please

[alexandre-antoi.bourrieau]

Hello,

I have a microstrip with a terminal voltage at total = 1V with port impoedance set to 50 ohm:

I want to calculate port impedance using Field Calculator : Zpv = V²/P.

For calculating V, I integrate E along the line :

using this formula :

and I got 1V so it work OK:

For calculating P, I integrate Poyting vector on this surface :

But after dividing quantity, I don't got 50 ohm but 318 ohm :

So it seems that my value for P is wrong no ?

Thanks you !

[Aymen Mzoughi]

HFSS can directly compute the port impedance so there is no need to go through the field calculator