User Cal
(User Level
Flatness
Correction)
The User Cal (user level flatness correction) func-
tion lets you calibrate out path variations with fre-
quency that are caused by external switching,
amplifiers, couplers, and cables in the test setup.
This is done by means of an entered power-offset ta-
ble from a GPIB power meter or calculated data.
When user level flatness correction is activated, the
set power level is delivered at the point in the test
setup where the calibration was performed. This
“flattening” of the test point power level is accom-
plished by summing a power-offset word (from the
power-offset table) with the sweep generator’s nor-
mal power level DAC word at each frequency point.
Up to five user level flatness correction power-offset
tables from 2 to 801 frequency points/table can be
created and stored in 681XXB memory for recall.
The GPIB power meters supported are the Anritsu
Model ML4803A and the Hewlett-Packard Models
437B, 438A, and 70100A.
LOCAL (FRONT
LEVELING
PANEL) OPERATION
OPERATIONS
SWITCH MATRIX,
AMPLIFIERS,
COUPLERS, ETC.
POWER
METER
RF
OUTPUT
DEVICE
UNDER
TEST
POWER
SENSOR
INPUT
FLATNESS
CORRECTED
OUTPUT
GPIB
681XXB SWEEP GENERATOR
GPIB
Figure 3-4.
Setup for Creating a Power-Offset Table (User Level Flatness Correction)
681XXB OM
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