Target I/Q Power Calibration

(E8267D Only)

This adjustment calibrates the power at the output of the I/Q multiplexer board that results in optimum adjacent channel power ratio. The adjustment is dependent on prior ALC and I/Q calibrations.

Targeted I/Q power is determined by the intersection of the distortion and noise curves exhibited by the output of the I/Q modulator. With known slopes for Distortion vs. I/Q Multiplexer Output Power and Noise vs. I/Q Multiplexer Output Power, an intersection point of the curves is determined and the I/Q power is set so that it does not exceed the optimum power level.

Test Equipment

Preferred Model

  

Spectrum Analyzer

E444xA1

  

External Baseband Signal Generator
Not required for Opt 601 or 602

E4438C Opt 402 and (001, 002, 601, or 602)

E8267D Opt (601 or 602)
E8267C Opt (002 or 602)

1.Select any model of PSA spectrum analyzer (E4440A, E4443A,E4445A, E4446A, E4447A, E4448A) that has a maximum frequency greater than or equal to the maximum frequency of the unit under test. An E4448A is required for units with Option 567. The E4448A frequency range is adequate for all PSG-D frequency configurations.

 

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 Target I/Q Power Calibration (Option 601, 602 Only)

 

Setup for Target I/Q Power Calibration (All models without Option 601,602)

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. Please check and ensure that the 856XE/EC series spectrum analyzer's external reference is connected. The spectrum analyzer will lock up and not take a sweep when external reference is selected and there isn't one connected to it.

  3. If this adjustment fails after step 1 and step 2, 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.

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