Agilent Technologies E4417A - Page 158

Measurement Uncertainty Analysis - Power Reference Level Test C
E4416A/E4417A Power Meters Service Guide C-137
CF is the value of the Calibration Factor of the Thermistor mount at 50 MHz.
M
s
is the mismatch magnitude between the DUT reference and the 8478B
sensor, which is equal to:
where,
P
s
is the reflection coefficient of the source (i.e. the DUT) and P
d
is the
reflection coefficient of the 8478B detector.
Hence,
Consider the measurement setup that exists in Table C- 1
P
o
is the total power output from the DUT. Of this power a proportion related
to P
d
is reflected back towards the source. The power subjected on the Agilent
432 would be:
But because a proportion of this total power related to P
d
has been reflected
Ps will again cause a reflection giving:
Figure C-1 Measurement Setup
M
s
2 P
s
P
d
⋅⋅=
meas
fV
comp
V
1
V
0
RCFM
s
,,,, ,(=
DUT
8478B
432A
Power Meter
P
s
P
d
P
o
1 P
d
2
–()
P
o
1 P
s
P
d
±()
2
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