Hi,
first, many thanks for the answers!
Of course I tried to give the resistor an equation with the variable
freq, but the software sets freq only to the starting frequency and
does not update it during the frequency sweep :-(
Tried f, fr, frequency also, but they stay at their predefined value
and cause errors if not predefined.
Software is some IC simulation spice from tektronix.
The RL ladder network emulating coaxial sheets seems clever, but it
changes L with frequency also, which I have to avoid as the L in the
model is constant with frequency.
http://www.eettaiwan.com/ARTICLES/2001AUG/PDF/2001AUG27_AMD_AN1541.PDF
Unfortunately my spice also does not have laplace sources so I am bound
with the Rskin=k*sqrt(f) model which also does not work as I described
above.
Now how to make R dependent and L independent?
Greg