R3765/67G Series Network Analyzer Operation Manual
7.5 Calibration
7-35
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The following signal flow graph shows an error model.
Directivity
:
The directional coupler/bridge for measurement of reflection de-
tects a reflection signal from DUT.
But actually it detects not only reflection signal but a little incident
signal. The limitation that can separate this reflection signal from
the incident signal is called “directivity”.
Source match
:
The error is produced by the reflection signal from DUT which was
reflected again from the signal source and then entered into DUT.
The reflection coefficient in this signal source is called “source
match”.
Load match
:
The signal passed through DUT is input into the receiver section,
where the signal is reflected according to the reflection coefficient
of the receiver section.
This reflected signal passes DUT again and returns to the signal
source. Then produces an error.
This reflection coefficient in the receiver section is called “load
match”.
Transmission tracking:
It’s the measurement frequency characteristics of transmission di-
rection.
Reflection tracking :
It’s the measurement frequency characteristics of reflection direction.
RF IN
E
LF
E
DF
E
SF
E
TF
E
RF
Directivity
Source match
Transmission tracking
Reflection tracking
Isolation
S
11M
E
DF
E
SF
S
11A
S
22A
S
21M
S
21A
E
TF
E
XF
E
LF
S
12A
E
RF
RF IN
S
22M
E
SR
E
DR
E
LR
S
11A
S
22A
S
21A
E
RR
1
S
12A
E
TR
E
XR
S
12M
Forward direction Inverse direction
(Forward direction)
(Inverse direction)
Load match
:
:
:
:
:
:
E
XF
E
LR
E
DR
E
SR
E
TR
E
RR
E
XR
1
