The maximum and minimum peak voltages measured on the line are
Let us define a quantity called ' Voltage Standing Wave Ratio (VSWR) ' as
Substituting for
and
we get
The VSWR is a measure of the reflection on the line. Higher the value of VSWR, higher is
i.e., higher is the
reflection and is lesser the power transfer to the load.
Since
, we get
VSWR of 1 corresponds to the
. That is the best situation.
Ideally for a perfect match VSWR = 1. However, generally a
is considered acceptable in all
experimental works.
and
we get 
i.e., higher is the
reflection and is lesser the power transfer to the load. 
, we get 
. That is the best situation. 
is considered acceptable in all
experimental works. 
