SWR

Related wiki pages Antennas, Gain, Propagation, Bands

Standing Wave Ratio - (SWR)

What is SWR?

When there is a mismatch between the output impedance of a transmitter and input impedance of an antenna, some of the signal - in the form of a wave - is reflected back down the transmission line to the transmitter. Standing waved of electrical energy will "appear" in the transmission line. SWR is the ratio:

amplitude (height) of the standing wave : amplitude of an adjacent node (central point on the wave form)

File:Vk4yeh standing wave.jpg

How is SWR calculated?

Online SWR calculator from VE3KL