User`s guide

4
If the correction frequency span is only a subset of
the start/stop frequency span set on the source, no
corrections will be applied to the portion of the
sweep that is outside the correction frequency span.
The following example illustrates how the data is
distributed within the user flatness correction array.
When utilizing user flatness correction, do not exceed
the 8360 ALC operating range. Exceeding the ALC
range will cause the output power to become
unleveled and eliminate the benefits of user flatness
correction. The ALC range can be determined by
subtracting the minimum output power (-20 dBm)
from the maximum specified power
1
. An Agilent
83620B has an ALC range of ≥30 dB (≥+10 to
-20 dBm).
When user flatness correction is enabled, the
maximum settable test port power is equivalent to
the maximum available leveled power minus the
maximum path loss (P
0 max
-P
path loss
). For
example, if an 83620B has a maximum path loss
of 15 dB due to system components between the
source output and the test port, the test port power
should be set to -5 dBm. When user flatness cor-
rection is enabled, this will provide the maximum
available power to the device under test (DUT).
The following glossary reviews the terms that will
be used throughout this note:
1
When the optional step attenuator is ordered on an 8360 with firmware released prior to November 1990, the attenuator will need to be uncoupled if the full
ALC range is required. This can be accomplished by selecting POWER [MENU] [Uncoupl Atten].
Figure 5. Array configuration example
array - the 1601 user flatness correction points that
will be summed with the internal calibration data
of the Agilent 8360. The array covers the entire
start/stop frequency range the user sets on the
instrument.
correction table – the user-supplied entries in
the array. Each entry in the table has a correction
component and an associated frequency component.
user flatness correction
correction frequency – the frequency component of
an entry where a correction has been or will be
measured and entered in the table.
correction frequency span – the frequency span
between the first and last correction frequency.
correction data – the power level correction
components of entries in the table.
cal factor – the calibration factors displayed on the
power sensor. By entering the appropriate cal fac-
tor for each measurement frequency on a power
meter, one can calibrate the power meter to a par-
ticular power sensor across the chosen frequency
range.
Assume that the user sets up the source to
sweep from 2 to 18 GHz but only enters user
flatness correction data from 14 to 18 GHz.
Linear interpolation will occur between the
correction entries to provide the 401 points
required for the 14 to 18 GHz portion of the
array. No corrections will be applied to the
2 to 13.99 GHz portion of the array.
Point number
No corrections applied 401 pts. data
0 1200 1600
2 GHZ 14 GHz 18 GHz
1st corr. freq.
Frequency
Number of points interpolated between
correction entries:
freq span between correction entries
stop frequency – start frequency
x 1600 – 1 = # pts
When correction frequencies are arbitrarily
spaced, the number of interpolated points
will vary.