Agilent Technologies Agilent 8163A

Return Loss Measurement A Background to Return Loss Measurement
194 Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Sixth Edition
If we substitute equation 3 into equations 2 and 4, this gives us the
following two equations:
If we subtract P
para
from equations 5 and 6, this gives us the following
equations:
If we divide equation 8 by equation 7, this gives us the following equations:
Thus we can use the equation below to calculate return loss:
The return loss of the reference reflection is given by:
P
Ref
c
1
M
Ref
R
Ref
M
ref
M
para
----- ---- ---- --- P
para
+=
(5)
P
DUT
c
1
M
DUT
R
DUT
M
DUT
M
para
---------------- P
para
+=
(6)