How to Configure and Run a Diagnostic RF System Stability Test

Watch this video to learn how to properly implement and analyze a diagnostic RF system stability test.

Configure and Run a Diagnostic RF System Stability Test:

The AARTS RF system is a sophisticated test instrument capable of independent adjustment and measurement of RF levels across multiple channels.

If you're observing unexpected results in your data on one of more channels or if you have a channel shut down unexpectedly, the most effective way to investigate this is typically by running a Stability Test for diagnostic purposes.

This video will walk through the process of setting up and running that test.

The first step will be to install RF thru cables on the idle channels that will be investigated. Disconnect the input and output cables from the fixture and install the cable used during the RF Cal 2 process in order to bypass the fixture. This will remove any variables from the test that could be introduced by the device under test and the fixture.

Once the cables are installed, new datasets will need to be configured for the stability test in edit limits.

This will likely first involve deleting the actual channels that were configured for the previous life test.

Testing with these data files can continue after the diagnostic test is complete by using the "Import and Tag" feature. Delete the necessary channels from the list by highlighting them. Then, right click and select "delete."

Then, select file, save and exit.

Re-enter "Edit Limits" and then select "Add Multichannel" to add the new channels to be tested.

In the storage folder field, create new data folders for any channel to be tested in edit limits. It can be helpful to store these results in a dedicated folder for diagnostic tests. Select save and exit to register those changes. Then select save and exit again to finish in edit limits.

Next, go to "Edit Levels" to configure the parameters of the test. Select the first channel to configure and then uncheck the following three boxes:

  1. Pre-RF Levels
  2. Post-RF Levels
  3. Include RF.

Turning off the two DC Level check boxes is clear because this will be an RF-only test. Turning off the Include RF flag seems strange at first, but this will prevent the system from maintaining a fixed RF input drive over the course of the test. This is extremely helpful in checking for variation in the input switch path for a particular channel.

Next, go into "DC Levels" and change the four source mode entries to Off. This ensures no voltage will be turned on to the DUT, and is also a required step for RF-only tests to run properly. With the channel now configured, apply these settings to any other applicable channels by selecting Apply, "Apply to Channels."

Return to "Edit Levels." Now select File, Save All and Exit to close out of Edit Levels, and click "Okay" to confirm your changes. The tests are now configured and ready to be run.

Go to "Life Test Monitor" next to start up the test.

Select Start/Stop, Auto Start, Start Channels, and enter the channels to begin the test.

Since we turned off the Include RF flag, we will need to manually turn on the RF drive for the channels to be tested. To do this, first minimize the Life Test Monitor screen to return to the Main Menu. We will need to access the RFU Control screen in order to turn on the RF for the channels running the Stability Test. Access to this screen is typically disabled when the test is running as a precaution, so an override is required to enable it. Press CTRL F2 to gain access and then Enter.

In RFU Control, first select one of the channels now running the diagnostic test. Enter a nominal RF Drive Level in the target box in the VGA Attenuator Control window. Then click "Program" to turn on RF Drive.

Repeat this for any other channels running the test.

Exit out of RFU Control and return to the life test monitor. Since the test is running in "Auto Start Mode", the last step will be to initiate data storage. You can do this for all channels by holding Control and clicking the "Active Channel button."

Let the stability test run for a number of hours and ideally over at least one night. You will then have measured data of the complete RF subsystem ready to review and check for any inconsistencies.

If you need assistance in interpreting your results, please SUBMIT A SUPPORT TICKET and provide your data folders and system folder for review.