Low Band Bypass Gain Calibration

This adjustment calibrates the GAIN ADJUST DAC on the A8 lowband output board (note that this feeds into the A6 Frac-N board for this cal). This DAC is used to control the RF power level that is incident upon the switched filters and subsequent RF amplifiers. This is accomplished by setting the control point for the Gain Adjust modulator. The goal of this calibration is to have sufficient power available at the amplifiers to have enough DUT output power available, while minimizing phase noise.

Test Equipment

Preferred Model

Alternate Model(s)

50 Ohm Terminator1

Depending on the DUT RF Output Connector, choose:

85138B (2.4mm)
or 909D (3.5mm)
or 909A, Opt 012 (Type N)

 

1. A 20 dB attenuator may be used as an alternative to a 50 Ohm Terminator.

 

Connections and Setup Procedures

  • All test equipment requires a 30 minute warmup period to ensure accurate performance.

  • In the following test setup, cables are designated as solid lines and direct connections are designated as dashed lines.

  1. Connect all test equipment as shown.

  2. Connect GPIB cables to all GPIB-controlled test equipment.

  3. While performing this adjustment, follow all instructions on the controller display.

 

Setup for Low Band Bypass Gain Calibration

 

In Case of Difficulty

If this adjustment fails, perform the following steps in order:

  1. Check the equipment setup (see above). If the setup is incorrect, make the necessary corrections and rerun the adjustment.

  2. If this adjustment fails with the equipment set up properly, refer to the troubleshooting section of the signal generator's service guide. If you do not have a printed copy of the service guide (Option OBW), one is available either on the CD-ROM that came with your signal generator shipment or on the Keysight Website.

  3. If you cannot correct the problem using the troubleshooting procedures in the Service Guide, obtain service from Keysight Technologies. Refer to Contacting Keysight Technologies.