YIG-Driver Pre-Tune Calibration

This adjustment calibrates the A5 Sampler YO drive to minimize phase-lock-voltage error and to improve linearity above 7 GHz.

An internal firmware routine is used to perform the calibration. The firmware routine can also be accessed from the front panel by pressing: Utility --> Instrument Adjustments --> Service Adjustments --> Yig Pretune Calibration.

The routine starts by setting the YO to 501 MHz (FL). A fine-lock routine is run that changes the value of the YO Pretune DAC on the A9 YIG Driver. While adjusting the YO Pretune DAC, the SMP_YO_PHSLK_ABUS node is monitored until the YO error voltage is minimized. The DAC setting is saved as low DAC limit (DL). The YO is set to 1000 MHz (FH) and the routine is run again to find a high DAC limit (DH). These values are used to determine the YO Offset and YO Gain values which, in turn, determine the YO Pretune DAC setting for a given YO frequency.

To improve YO linearity, a second routine is run. This routine sets three different frequencies and measures the DAC values and error voltages. The routine uses these DAC values along with the YO Offset and YO Gain values to determine new YO Pretune DAC values which are stored as a third term and used above 7 GHz.

Connections and Setup Procedures

  1. Connect a GPIB cable between the controller and the signal generator being calibrated.

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

 

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.