Agilent Technologies E4418B Service Manual page 141

where,
P
s
coefficient of the 8478B detector.
Hence,
Consider the measurement setup that exists in Figure B-1
P
o
reflected back towards the source. The power subjected on the 432 would be:
But because a proportion of this total power related to Pd has been reflected Ps will
again cause a reflection giving:
So the total power incident or measured by the 432 Power meter is given by:
Note
Agilent E4416A/E4417A Service Guide
Measurement Uncertainty Analysis – Power Reference Level Test
is the reflection coefficient of the source (i.e. the DUT) and P
(
P meas = f V comp V 1 V 0 R CF M s
POWER
REF
DUT
P
d
Figure B-1: Measurement Setup
is the total power output from the DUT. Of this power a proportion related to P
P o 1 P d
(
P
o
P o 1 P d
  –
In all cases P is extremely small therefore P
d
, , , , ,
P
S
8478B
2
–
 

2
± )
1 P P
s d
2 2
⁄ ( ± )
1 P s P d
 
 
² terms tend to zero leaving.
d
Measurement Introduction
is the reflection
d
)
432A
Power
Meter
is
d
B-3