Atec Agilent-8563E - Manual (Page 126)

ESG Family Signal Generators Adjustments
Prelevel Calibration, Digital
Calibration Guide 5-29
Prelevel Calibration, Digital
Description
This test calibrates the PRE LEVEL REF DAC on the output board. This DAC is used to
control the RF power level that is incident upon the marble I/Q modulator by setting the
control point for the prelevel loop. The prelevel loop detector is on the output of the marble
I/Q modulator, its drive circuitry on the output board, and its RF modulator on the
synthesizer board. This calibration ensures that there will be sufficient power available at
the marble I/Q modulator to perform the desired modulation while minimizing
intermodulation distortion when the digital modulation is activated. The signal generator
is set to a frequency and the auxiliary output amplitude level is adjusted using the PRE
LEVEL DAC to within the specified tolerance of the desired value. This process is repeated
for all the frequencies in the marble I/Q modulator index array. The results are then stored
in the signal generator’s firmware.
Required Test Equipment
• HP/Agilent 438A Power Meter
• HP/Agilent 8482A Power Sensor
Procedure
Figure 5-25 Prelevel Calibration Setup
1. Connect the equipment as shown above.
2. Preset all of the equipment.
3. Follow the instructions as they appear on the controller’s display.