Keysight Technologies FieldFox A Series, User Manual

Page: 577 / 756

Keysight N9927-90001 User’s Guide 577
Noise Figure Mode (Option 356 – CPU2 Only)
How to Define a Noise Figure Measurement
sources in the measurement and in the user calibration. And, in the case of
very low power output DUTs (<15 dB gain + noise figure), by using an isolator
on the input of the preamplifier.
Electromagnetic interference
DUTs, preamplifiers, noise sources, and connectors may all potentially be
affected by radiated signals present in the test environment. Care should be
taken to establish an appropriate test environment for the noise figure
measurement.
DUT oscillations, microphonic behavior, etcetera
Any instability in the DUT will cause unaccounted noise measurement
uncertainties.
Entering Uncertainty Information
In addition to information gathered during the measurement, the following
information must be provided by the user in order to determine the noise
measurement uncertainty:
— DUT Reflection Coefficient
For this section, see also “Overview of Softkey Menus” on page 555
( Uncertainty > DUT on page 559 ).
DUT Reflection Coefficients values may be imported to a DUT table from
*.snp or *.csv Files, entered by editing a DUT table, recalled as a previously
saved DUT table (in a *.dut file), or set as a spot value to be applied across
all frequencies.
DUT and preamplifier *.snp files may be generated in the FieldFox VNA
mode, and then imported into the Noise Figure mode.