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FieldFox User’s Guide
This setting survives an Instrument Preset.
Waveguide Calibrations
In general, calibrating with Waveguide is very similar to calibrating with coax.
However, most coax mechanical Cal Kits have standards that can be used over a
very wide frequency range. Waveguide Cal Kits are used over a narrow frequency
range. Therefore, it is VERY IMPORTANT to set the frequency range of the
measurement WITHIN the frequency range of the waveguide Cal Kit. Otherwise,
an error message will appear during the ‘Calculating Steps’ portion of the
calibration.
Waveguide Cal Kits
Agilent sells two waveguide Cal Kit series: the premium 11644A series and the
economy N9911X series. Both are available online at
Effective Velocity Factor
Velocity factor is the speed at which an electromagnetic signal passes through
the transmission medium relative to the speed of light. This value is important
when distance is being calculated in DTF measurements (CAT mode) and Time
Domain (NA mode).
When the media is waveguide, the velocity factor changes with frequency.
FieldFox calculates this ‘effective’ velocity factor automatically. However, the
settings are different for CAT mode and NA mode.
CAT Mode - How to make Waveguide settings
These settings are necessary ONLY when making DTF measurements.
Press
Measure 1
then select a
DTF
measurement.
Press
Meas Setup 4
Then
Settings
(Learn how to use the Quick Settings table on page 22.)
Set
Media
=
Waveguide.
Frequency Mode =
BandPass
is automatically
selected for you.
Scroll down to
Waveguide Definitions
. Select the
Waveguide Standard
being
used. If your waveguide standard is NOT listed:
o
Select
User Waveguide.
Then press
Done
.
o
Then
DTF Cable Specifications
, then
Edit/Save/Recall Cables
, then
Edit
Cable.
o
Scroll to set
Waveguide Definition
and set
VF Corr
= Auto.
o
Then set the
Min, Max
, and
Cutoff Frequencies
.
Set
Cable Correction
=
Auto.
The Effective Velocity Factor is calculated
automatically based on the frequencies of the waveguide standard. To override
this setting, set Cable Correction =
Man
.
NA Mode - How to make Waveguide settings
These settings are necessary ONLY when your measurement requires electrical
delay or port extensions, or if using Time Domain Transform.
Press
Meas Setup 4