Agilent Technologies 8719D, Руководство пользователя

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The quality of the error-correction is limited by two factors: (1) the difference between the
model of the calibration standards and the actual electrical characteristics of those standards,
and (2) the condition of the calibration standards. make the quality measurement
calibration, follow the suggestions below:
Use the correct standard model.
n
Inspect the calibration standards,
n
Clean the calibration standards.
n
Gauge the calibration standards.
n
Use correct connection techniques.
If you want to use calibration standards other than the default sets, you must change the
standard model (refer to “Modifying Calibration Kit Standards” located later in this chapter).
After you enter the mathematical model for the new calibration standards, the analyzer can
then use the model that corresponds to the new standards.
Load Standards
Measurement calibrations requiring load standards provide additional menus to specify the
load(s). For broadband calibrations, use either a broadband load or, for the highest level of
accuracy, a combination of and sliding loads For measurements above 3 in
3.5 mm, the load calibration can be omitted. For measurements below 3 in
3.5 mm, the load alone is sufficient. If you try to use only a sliding load or only
a load beyond these frequency cutoff points, the message
CAUTION: ADDITIONAL
STANDARDS NEEDED
will be displayed to indicate that both loads are required. See 5-3 for
the frequency cutoff points of different connector types.
5-3. Frequency Cutoff Points of Loud
Connector Type
Broadband Load (50 MHz to 20
Load Sliding
3.5 mm
I
50
MHz to 3
I
3
to 20
I
I
50
MHz to 2 I
2
to 20
I
Type-N
I
50
MHz to 2
I
2
to 20
I
2.4 mm
I
50
MHz to 4
I
4
to 20
I
Compensating for the Electrical Delay of Calibration Standards
Short and open calibration standards in the and connector types
have a certain amount of electrical delay. The analyzer compensates for this delay by offsetting
the calibration results by the total amount of electrical delay caused by the calibration standard
in both the forward and reverse direction. As a result, if these standards are measured after a
calibration, they will not appear to be “perfect” shorts or opens This is an indication that
your
working
and that it has successfully performed a calibration.
Optimizing Measurement