Agilent Technologies 4395A - Page 369

Determining
Expected
System
performance
T
able 11-9.
Reection Measurement
Uncertainty
W
orksheet
In
the
columns
below
,
enter the
appropriate values
for each
term. Frequency:
Error
T
erm
Symbol dB
V
alue
Linear
V
alue
Directivity D
Reection
tracking
T
r
Source
match
M
s
Load
match
M
l
Dynamic
accuracy
(magnitude)
1
A
m
Dynamic
accuracy
(phase)
1
A
p
Multiplexer
Switching
Uncertainty
(magnitude)
U
m
Multiplexer
Switching
Uncertainty
(phase)
U
p
S
11
S
11
S
21
S
21
S
12
S
12
Noise
oor
N
l
High
level noise
N
h
Connector
reection
repeatability
R
r1
,
R
r2
Connector
transmission
repeatability
R
t1
,
R
t2
Magnitude
drift
due
to temperature
T
rd
(mag)
Phase
drift
due
to
temperature
T
rd
(phase)
Cable
reection
stability
S
r1
,
S
r2
Cable
transmission
phase
stability
S
t1
,
S
t2
Switch
Tracking
T
sw
Switch
P
ort
Match
M
sw
Magnitude
Combine
Systematic
Errors
.
In
the
space
provided,
enter
the
appropriate
linear
values
from the
list
of
errors
.
Then
combine
these
errors
to
obtain
the
total
sum
of
systematic
errors
.
(1
+
T
sw
)
2
(D
+
S
r1
) ( + )
2
(
+ )
=
(k)
(T
sw
+
T
r
)
2
S
11
( + )
2
= (l)
(M
sw
+
S
r1
+
M
s
)
2
S
11
2
S
11
( + + )
2
2 = (m)
(M
sw
+
S
r2
+
M
l
)
2
S
21
2
S
12
( + + )
2
2 = (n)
(A
m
+U
m
)
2
S
11
( + )
2
= (o)
Subtotal:
k
+
l
+
m
+
n
+o
+ + + + = (S)
Combine
Random
Errors
.
In
the
space
provided,
enter
the
appropriate
linear
values
from
the list
of errors
.
Then combine
these
errors
in
an
RSS
fashion
to
obtain
a
total
sum
of
the
random errors
.
3
2
N
l
3
2
= (w)
3 2 N
h
2 S
11
3 2 2 = (x)
R
r1
+2
2 R
t1
2 S
11
+R
r1
2 S
11
2 S
11
+2 2 2 + 2 2 = (y)
R
r2
2 S
21
2 S
12
2 2 = (z)
p
w
2
+
x
2
+
y
2
+
z
2
p
2 + 2 + 2 + 2 = (R)
Subtotal: S+R + = (V
r
)
Total Magnitude Errors:
E
rm
(linear) = V
r
+T
rd
(mag) 2 S
11
+( 2 )=
E
rm
(log) = 20 Log(1 6 E
rm
/S
11
) 20 Log(1 6 / )= dB
Phase
E
rp
= Arcsin[(V
r
0 (A
m
+U
m
) 2
S
11
)/S
11
]+T
rd
(phase) + 2 2 S
t1
+
A
p
+U
p
Arcsin[( 0 ( + ) 2 )/ ]+ +2 2 + +
= 6 deg.
1 With IF bandwidth of 10 Hz.
Specications and Supplemental Characteristics 11-53