Agilent Technologies PSA Series User Manual page 35

Figure 2-2 Ranges and Relationships
Z
O
Line Impedence
Z
L
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
=
O
RL
∞ dB
SWR
1
ρ
0
V ρ
1 +
max
= ----------- - = ----------- - =
1 ρ
V –
min
Measurement Concepts
Equations and Conversion Table
Load
(Z - Device
L
Impedance)
= 0 , ∞
Z
L
0 dB
∞
1
– RL
----------
20
1 + 10
-----------------------
– RL
----------
20
1 10 –
ranges.vsd
35