Teaching transmission line transients using computer animation

Transmission line theory in electromagnetics comes alive when the travelling waves are animated on a computer screen, using program "BOUNCE". Fundamental concepts such as "travelling wave", "reflected wave", and "load matching" are forcefully demonstrated in the classroom. Problems using series connections of dissimilar line, shunt loads and branches can be readily examined. Transmission line theory is applied to problems in the design of tri-state logic circuits that cannot be solved readily by hand, using animation to show how the voltage waveforms arise. Animation is used with a sinusoidal generator to illustrate the evolution to the sinusoidal steady state, as an introduction to solving transmission line circuits with phasors. Students are encouraged to run BOUNCE at home as a computational laboratory to verify their solutions to homework problems. This paper presents the BOUNCE program, and some of the demonstrations with BOUNCE that are used in the classroom.