(VSWR)
The ratio of the sum of the magnitudes of the incident and reflected
power to the difference of the magnitudes of the incident and reflected
power at a point on a transmission line, expressed as a ration of n : 1:
VSWR = {Vinc + Vrefl} / {Vinc  Vrefl} : 1
VSWR is an indicator of impedance match. A VSWR of 1:1 represents
a perfect match; infinite:1 a perfect mismatch or reflection. For good
cascadability, the VSWR of a component should typically be better
than 2:1.
VSWR can be translated into return loss using the equation
RL = 20 log10(VSWR)
It can be calculated from the reflection coefficient using the equation
VSWR = (1 + ) / (1  )
