Anritsu 681XXC - Manual (Page 100)

User Cal
(User Level
Flatness
Correction) The User Cal (user level flatness correction) func-
tion lets you calibrate out path variations with
frequency that are caused by external switching,
amplifiers, couplers, and cables in the test setup.
This is done by means of an entered power-offset
table 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 signal 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 681XXC memory for recall.
The GPIB power meters supported are the Anritsu
Models ML2437A, ML2438A, and ML4803A and the
Hewlett-Packard Models 437B, 438A, and 70100A.
681XXC OM 3-67
LOCAL (FRONT LEVELING
PANEL) OPERATION OPERATIONS
S W I T C H M A T R I X ,
A M P L I F I E R S ,
C O U P L E R S , E T C .
P O W E R
M E T E R
R F
O U T P U T
D E V I C E
U N D E R
T E S T P O W E R
S E N S O R
I N P U T
F L A T N E S S
C O R R E C T E D
O U T P U T
G P I B 6 8 1 X X C S I G N A L G E N E R A T O R
G P I B
Figure 3-4. Setup for Creating a Power-Offset Table (User Level Flatness Correction)