Specifications

6
3. Power meter calibration (optional)
The 8510C network analyzer provides leveled
power at the test set port with a specified varia-
tion of less than 2.1 dB at 50 GHz. The power
meter calibration feature is available to provide
more accurate settable power when required and
can also serve to remove the frequency response
errors of the cables and adapters between the test
set and the AUT. If a power meter calibration is
performed it should be done prior to a measure-
ment calibration. Power meter calibration with the
8510C family is compatible with the Agilent 437B
and 438A power meters.
4. Measurement calibration
A measurement calibration characterizes and
removes the effects of the repeatable variations (or
systematic errors) in the test setup. Systematic
errors include frequency response tracking, direc-
tivity, mismatch, and crosstalk effects. A full two-
port calibration provides the greatest measurement
accuracy, but in some situations it may be more
practical to use other calibration techniques (i.e., a
response calibration for transmission-only meas-
urements or a one-port calibration for reflection-
only measurements). For more information see
Appendix B, “Accuracy considerations.”
After a calibration has been performed, “C”
appears to the left of the display to indicate that a
measurement calibration is on. Any attenuation
that is used on the input or output of the AUT
should be included in the calibration of the system
to remove its effects from the measurement of the
AUT.
Operating considerations
If you perform a factory preset ([RECALL]
{MORE}{FACTORY PRESET}) the power is set to
the maximum leveled value (in the highest power
range) of +10 dBm. If the AUT could be damaged
by this power level or will be operating in its non-
linear region, it should not be connected until the
power is set to a desirable level.
A useful feature for the testing of power-sensitive
devices is the user preset feature on the 8510C.
This allows the user to specify an instrument set-
ting for a particular measurement and to store it
away by pressing [SAVE] {USER PRESET 8}. Later,
when the green [USER PRESET] key is pressed,
these same conditions are recalled with the power
level and/or internal step attenuator set to the
appropriate level, preventing potential damage to
the AUT.
Measurement examples
The measurement examples described in this note
were made on an 8510C network analyzer with an
83651A source and 8517B Opt 007 test set. A full
two-port calibration was performed (except where
noted) for the greatest accuracy for both transmis-
sion and reflection measurements of the two-port
device. The amplifier under test is an 8348A ampli-
fier operating over a 2 to 26.5 GHz frequency
range. Other sources and test sets may be used, but
differences in frequency range and available out-
put power will exist.