Agilent Technologies PSA Series Manual page 35

Figure 2-2 Ranges and Relationships
Z
O
Line Impedence
Z
VSWR
Where: RL is the measured return loss value.
Note that a VSWR of 1 (sometimes referred to as 1:1) means that all of
the transmitted incident power is absorbed at the load and no power is
reflected back. (This assumes a perfect impedance match.) Similarly, an
infinite VSWR is for a perfect open or short, where all of the incident
power is reflected back.
Chapter 2
Incident
- Transmission
Reflected
Z
=
L O
∞ dB
1
0
V
ρ
1
+
max
----------- - ----------- -
= = =
1 ρ
V
–
min
Equations and Conversion Table
Load
(Z - Device
L
Impedance)
Z
L
RL
SWR
ρ
RL
–
----------
20
1 10
+
-----------------------
RL
–
----------
20
1 10
–
Measurement Concepts
= 0 , ∞
0 dB
∞
1
ranges.vsd
35