http://circuitcalculator.com/wordpress/2007/03/06/transmission-line-calculator/#more-51The Excel based tool ... calculates the capacitance and inductance per unit length as well as the impedance of a transmission line. It may be applied to wires, PCBs, etc.
A cross section of the transmission line is drawn into the Excel grids using different colors to represent the conductor, shield (return), and insulator. A finite element model of the transmission line is then solved with 1 Volt applied to the conductor with respect to the shield. The voltages throughout the insulator are found. This allows the stored energy, capacitance, inductance and impedance to be found.
While the copyright says:
... the instructions tell you to download this program, which I suppose qualify as permission.Copyrights
The web calculator scripts on this site are copyrighted and may not be used outside of this site without permission. Copying and re-posting on another site without licensing is strictly prohibited. Contact us if you would like to license a script or if you are in need of a custom script.
--Rich