What is Standing wave?
This page explains basics of standing wave and provides useful links.
In a mismatched terminated line, the incident and reflected signals interfere to produce
a standing wave pattern along the line. current and voltage standing waves are 90
degree out of phase along the transmission line. The magnitude of the standing waves is measured
using SWR(Standing Wave Ratio) as defined below.
SWR = (max. voltage or current)/(min. voltage or current)
In other words, reflected wave interferes with the forward wave and two tegether add at some point and cancel each other at some point due to phase change and produce a stationary interference pattern known as standing wave.