By Eric Bogatin, Originally published in PCD&M Magazine, Jan 2000.

Ever wonder what characteristic impedance really means, without invoking equations like the ratio of inductance and capacitance, or without reverting to the solution to the wave equation?

This article will give you a precise, intuitive feel for the instantaneous impedance a signal sees when propagating down a transmission line and how this relates to the characteristic impedance of the line. Finally, you’ll understand what impedance an ohmmeter will read if connected to the front of a 50 ohm line. All will be revealed.