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U9361C/F/G/M RCal Receiver Calibrator Measurement Guide
RCal Software – Calibration and Application
— Plan for how the signal analyzer will be used after calibration, so that the corrections are valid
for later changes in measurement parameters.
— Start with a a simple configuration and gradually configure for higher complexity. For example,
start with a single row, a small number of frequency steps, and a small range of attenuation
steps before further increasing these values as needed.
— In general, leave
Match State
set to
False
. See
“How to Utilize Match State” on page 18
for
more information.
— If you use the “Duplicate Row” feature, verify that the original row works correctly, and doesn’t
take an excessively long time, before copying to another row.
Multiple SA Input Ports and RCal Modules
Most signal analyzer systems employ a single input port. However, some analyzers (such as the
N9041B) have more than one input. If you need to calibrate both inputs, create a Cal Group for
each RF input port, since each Cal group may choose which module is associated with that group.
How to Utilize Match State
Acquisitions rarely match the exact hardware state at which the original RCal correction was
performed. The stored correction must be converted to the correction required for the exact
hardware acquisition state. This conversion is controlled by the
Match State
parameter within the
RCal configuration window.
If you want to only apply corrections to test setups that exactly match the state of their RCal
calibration(s), you should set the
Match State
to
True
. If you want to apply RCal corrections to
similar hardware states that may not exactly match the original hardware calibration state, you
should set the
Match State
to
False
. When the
Match State
is set to
False
, the following rules are
followed:
— Situations that are “close enough” will use the closest available correction.
— Situations that are too different will never be selected even when the
Match State
is set to
False
.
— Situations that are in between will utilize interpolation to get the desired correction.
Multiple Rows, Overlap, and Dual Corrections
If you create multiple rows, calibrate them, and select Apply in more than one row, the RCal system
may raise apply-time warnings. As long as one row matches the current state, the calibration will
be applied successfully for that row despite the warning.
If two or more rows both match state, they are considered overlapping and yield a
double-correction. This overlap may be over a
portion
of the spectrum trace. This usually is
undesired, and should be avoided or fixed by:
— Selecting Apply in a single row, or fewer rows, until the warning goes away, or configuring RCal
to avoid overlap.
