HP 8712ES User Manual page 262

NOTE
Calibrating for Increased Measurement Accuracy
Calibration Choices
Default 2-Port
Restoring the default two-port calibration recalls error correction arrays
that were calculated at the factory or during servicing and then
permanently stored in memory. This two-port calibration was performed
using full band (entire frequency span) and 401 frequency points, and
corrects systematic errors caused by frequency response, load match,
source match, and directivity. It is quick and convenient but not as
accurate at narrow frequency spans. The calibration reference planes are
at the analyzer's port 1 and port 2, so if you use cables in your test setup
you should adjust the port extensions to match the electrical lengths of
the cables (see "Port Extensions" on page
achieved by performing a user-defined two-port calibration. When using
the default 2-port calibration to measure the cable supplied with the
analyzer, the measured delay is approximately 3 ns. When a two-port
calibration is selected, the analyzer automatically measures all four
S-parameters. To quickly view each of the four S-parameters press
Trigger
MENU
softkeys under the
adjust the scaling to view each of the S-parameters.
When toggled on, the
systematic errors caused by crosstalk. To select it, press
User 2-Port Isolation on OFF
calibration always measures the same parameters, regardless of the
setting of Isolation on OFF
calibration standards are required when you enable the isolation
calibration feature. When toggled ON, this feature will change the
analyzer's calculations before displaying the data. Crosstalk can be a
problem with high-isolation devices and high-dynamic range devices.
Since this isolation calibration adds noise to the error model, you should
only select it if it is really needed.
Response
A response calibration prompts you to connect a through cable as the
calibration standard, and then measures it across the frequency band
you have defined, using the number of points you have defined. This
measurement is used to correct systematic frequency response errors. It
does not correct for source and load match.
6-16
Hold
, and then press the desired S-parameter
or
MEAS 1 MEAS 2
Isolation on OFF
Default 2-Port
. Therefore, no further measurements of
5-18). Best accuracy would be
menu. You may need to
softkey allows you to remove
CAL
. A two-port
ES User's Guide