# Skin effect (a-c resistance and internal inductance) calculations

Select appropriate form and input parameters, then click button.

## 1. Solid circular conductors (internal conductor of coaxial cable)

## 2. Tubular conductor

Replace outer and inner diameter for outerconductor of coaxial cable.

## 3. Bimetal conductor (copper clad steel in coaxial cable)

Commentary
Attenuation of cable is determined from the a-c resistance of conductor,
and phase distorsion of cable is determined from the internal inductance
of conductor. And these calculations result in eddy current calculation
of the conductor considering following factors.

- skin effect
- proximity effect
- eddy current in other sorrounding conductors

Skin effect is the largest of these.
But, only few simple cases are calculated analytical method using complex
**Bessel** functions.
Here are simple but impotant cases frequently used in many design.

In fact, isolated single conductor rarely exist.
But center conductor of coaxial cable is just this case.

Results of computation are the ratio of AC resistance for DC resistance,
DC resistance, AC resistance and **internal inductance** of the conductor.

Internal inductance is the inductance due to the magnetic field
inside the conductor.

In addition, the permeability of the air is 4e-7 * π (H / m),
and condctivity of copper is 5.8e7 (G / m)

1999-04-20, Kouichi Hirabayashi