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From: David Jefferies
Date: 30 Dec 2002
Time: 06:37:59
Remote Name: 195.92.168.165
Bill,<><><>Greetings. If you have a voltage between two separated points then you can divide the voltage by the separation distance and find an average E field (volts/metre). If the voltage changes with time, as in an antenna, then the E field changes with time. Also this happens between the wires of a transmission line. There is therefore a changing E field and this forms displacement current. If you consider the two individual wires of a transmission line, they carry equal and opposite currents. The current is not constant along the line length. If you consider a little length along one of the conductors, the current in along the wire minus the current out along the same wire equals the displacement current leaving the little length, which it must to satisfy Kirchoff. Send me a postal address and I'll write out the transmission line maths for you as a 2003 New Year present. David Jefferies, University of Surrey, Guildford GU2 7XH UK.