Definition of Terms
Specifications
Agilent 81618A/9A and Agilent 81622B/3B/4B/6B/7B/8B User’s Guide, Second Edition
23
Definition of Terms
This section defines terms that are used both in this chapter and
“Performance Tests” on page 35
.
Generally, all specifications apply for the given environmental
conditions and after warmup time.
Measurement principles are indicated. Alternative measurement
principles of equal value are also acceptable.
Averaging Time
Time defining the period during which the power meter takes readings
for averaging. At the end of the averaging time the average of the
readings is available (display- or memory-update). Symbol
T
avg
.
Linearity
The linearity error is defined as the relative difference between the
displayed power ratio,
D
x
/D
0
, and the actual (true)
power ratio
P
x
/P
0
caused by changing the displayed power level from the reference level,
D
0
, to an arbitrary displayed level,
D
x
. Symbol
N
.
if expressed in %
if expressed in dB
Conditions:
reference level 10
µ
W, displayed power levels within the
specified range, zero less than specified time prior to measurement.
Note 1:
ideally
N
= 0 %, respectively 0 dB.
Note 2
: the power-dependent nonlinearity,
N
(
P
x
), can alternatively be
expressed by the following formula:
where
r
(
P
) is the power-dependent responsivity (for a power meter,
the responsivity is defined as the ratio of displayed power to actual
input power).
N
D
x
D
0
⁄
P
x
P
0
⁄
-----------------
1
–
è
ø
æ
ö
100
=
N
dB
10
D
x
D
0
⁄
P
x
P
0
⁄
-----------------
è
ø
æ
ö
log
=
N P
x
( )
r P
x
( )
r P
0
( )
–
r P
0
( )
---------------------------------
=