User`s guide
3-130 Agilent E6432A Microwave Synthesizer User’s Guide
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I/Q Calibration (Option UNG Only)
I/Q Calibration (Option UNG Only)
Performing an I/Q Calibration is necessary for optimum performance of
the I/Q modulator.
• Internal I/Q Modulator Calibration
Due to the inherently sensitive nature of I/Q (vector) modulators, it is
recommended that a calibration be performed before each use, when I/Q
signal levels being used have changed, if the environmental
temperature has changed significantly, or if a long period of time has
elapsed since the last calibration. (For complete specifications, refer to
“Specifications and Characteristics” on page 6-1)
• External I/Q Source Calibration
If you would like to account for imperfections or impairments in the
external I/Q source signals being used, perform an external I/Q
source calibration. If the external I/Q sources being used have no or
little I/Q impairments (where the gain balance is unity and the dc
offsets are close to zero), performing an external I/Q source
generator calibration is not necessary.
For further information about I/Q calibration, refer to
Understanding I/Q Calibration.
To Perform an I/Q Calibration
1. Turn on the RF Output power of the synthesizer.
2. From the pull down View menu, point to Calibration, and select I/Q
Calibration.
3. When the I/Q Calibration Dialog Box appears, select the
Calibrate I/Q Modulator button.
An iterative calibration algorithm will run and make corrections for
the impairments within the synthesizer by adjusting the Gain,
Offset, and Quadrature adjustment DACs. This portion of the I/Q
calibration does not account for impairments due to external I and Q
sources.
You may verify the success of your I/Q modulator calibration by
referring to the procedure, To Check the Level of the Carrier
Feed-Through.