Q376 : Resistance, Capacitance and Inductance in HIFREQ
Question What is it the meaning of Ri, Li, and Ci in the conductor-type definition screen in HIFREQ? I understand that these magnitudes do not represent the R, L and C of transmission lines, do they? Can I introduce these distributed values somewhere?
Answer The Ri, Li, and Ci parameters define a "lumped" impedance consisting of a series combination of a resistance (Ri), inductance (Li) and Capacitance (Ci); this impedance is inserted in the middle of all segments having this conductor type. This makes it possible to introduce regular circuit elements in HIFREQ.
These do not represent the impedance per unit length of the conductors. Presently, it isn't possible to specify this distributed impedance directly in the software. What you can do is to try and guess a suitable resistivity, permeability and inner radius to yield the desired impedance. (The impedance is reported in HIFREQ's output file.)