Keysight Technologies FieldFox A Series, User Manual

Page: 581 / 756

Keysight N9927-90001 User’s Guide 581
Noise Figure Mode (Option 356 – CPU2 Only)
How to Define a Noise Figure Measurement
Using ENR Tables
ENR tables are used to define the noise source(s) used in DUT measurements,
receiver, and user calibration(s). Additionally, ENR tables are used along with
DUT tables, preamplifier tables, and information collected during the
measurement to compute the measurement uncertainty. Refer to Figure 29-10
on page 582 .
— Both gain and noise figure measurement accuracy will be enhanced by
using a noise source with as low a reflection coefficient as possible for both
the noise figure measurement and the user calibration.
— It is not necessary to use the same noise source in the user calibration as
will be used in the measurement. In some cases, it might be better to use a
different noise source in the user calibration than will be used in the
measurement. If this is done, it is important to select the ENR table for the
calibration noise source prior to the calibration. And, then to select the ENR
table for the measurement noise source prior to measuring the DUT.
See also,
“Calibration Wizard” on page 585 .
How to Create an ENR Table
To create an ENR table:
This procedure assumes you have previously set your frequency, resolution
bandwidth, and number of points. Refer to “Example: Typical Noise Figure
Measurement Procedure” on page 554 .
For this procedure, refer to Figure 29-10 on page 582 .
1. Press Measure > Noise Source > ENR Mode Table (default)
2. Then ENR Table Edit/Save/Recall
3. Then choose:
Edit ENR Table (to modify the currently loaded ENR table)
New ENR Table (to create a new table)
Save ENR Table (to save any changes to the currently loaded ENR table)
Recall ENR Table (to recall a previously saved table)
Back (to return to previous softkey menu)
4. Then edit the table as necessary for your devices and measurements by
entering in Header, Auto-populate, ENR, ENR uncertainty, On
|Γ
|, and Off
|
Γ
|. Refer to Figure 29-10 on page 582 .