ALC

Use this adjustment to achieve a four-point fit of power level accuracy. Four calibration (cal) constants are used to calibrate the ALC. They represent settings for the BULK R DAC, the DETECTOR OFFSET DAC, the LOG OFFSET DAC and the ALC REF DAC. The LOG OFFSET DAC cal constant is used to center the operating point of the ALC loop about the reference DAC setting of 2048. The DETECTOR OFFSET DAC cal constant is used to calibrate the accuracy at low power levels. The BULK R DAC cal constant is used to calibrate the accuracy at high power levels. The ALC REF DAC cal is comprised of two frequency dependent terms; a linear and quadratic gain term. These values are used as inputs in the ALC control algorithm to determine the appropriate ALC REF DAC setting for the requested output power level at a given frequency.

This adjustment defaults the calibration data related to the 0 dB internal step attenuator. The Power Flatness adjustment must be run to determine/store new calibration data.

Required Test Equipment

Test Equipment

Recommended Model

Alternate Model

Power Meter

N1914B

N1914A1
N1913A
N1913B

E4418A
E4418B
E4419A
E4419B

Power Sensor

N8482A

E9304A
E9304A H18
N8482A CFT
8482A2

  1. Power meter N1914A with serial numbers ranging between MY00000000—MY53040007 require Service Note 07 to be applied for measurement repeatability. Please have this service note applied or verify it was applied before using this power meter. The affected service note is N1914A-07.

  2. Not allowed for the following product configurations:

    The dynamic frequency range of this sensor is insufficient for these models.

Connections and Setup Procedures
  • All test equipment requires a 30 minute warmup period to ensure accurate performance.
  • In the following adjustment 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.

 

Power Meter Zero and Cal Setup

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.