Performing Acquisition Phase Calibration

Acquisition phase calibration is a required step to use multichannel relative phase and amplitude corrections on your system. Acquisition phase calibration adjusts the relative channel-to-channel phase and amplitude performance of the VSTs. Successful calibration results in a calibration file or files being saved to disk on the PXIe controller.

This calibration setup requires no additional cable components.
Complete the following steps.
  1. Connect the cabling for acquisition phase calibration.
    1. Disconnect the SMA to SMA cable from the CH1: RF OUT connector on the LO Amplifier.
    2. Use the SMA to SMA cable to connect the S port on the RF IN LO Splitter to the RF OUT connector on VST_00.
      Figure 1. Acquisition Phase Calibration Cabling for 2-Channel Systems


      Figure 1. Acquisition Phase Calibration Cabling for 4-Channel Systems


      Figure 1. Acquisition Phase Calibration Cabling for 8-Channel Systems


      Figure 1. Acquisition Phase Calibration Cabling for 16-Channel Systems


  2. In InstrumentStudio, click Manual layout.
  3. In the Edit Layout window that opens, under RPS Plugins, select System Calibration: Phase Calibration and then select Create a large panel. Click OK.
    A panel opens.
    Figure 1. Acquisition Phase Calibration Panel


  4. Ensure the IP address and port information are correct and click Connect to establish a connection to the gRPC server.
  5. Set the parameters in the Phase Calibration panel.
    • Calibration Instruments—Select the VSTs in the system.
    • Signal Source—Select the name and port number of the acquisition phase calibration signal source VST from step 1.
    • Calibration Mode—Select Acquisition Phase Coherent or Acquisition Phase Aligned.
    • Multi Chassis—Enable for any systems with VSTs placed in more than one chassis, such as 8-channel or 16-channel systems.
    • Bandwidth Start, End, and Delta—Set the bandwidth values in Hz. The software appends Hz to the values.
    • Frequency Start and End—Set the frequency values in Hz. The software appends Hz to the values.
    • LO Share—Select None, Daisy Chain, or Calibrated Star.
      Note For LO star systems, you must have a LO calibration file (created during Acquisition LO calibration).
    • Frequency—If Star was selected for LO Share, select a single frequency, Range, or All.
    • Level—Set the Start, End, and Delta values in dBm. The software appends dBm to the values.
    • Path Loss—Set the Start, End, and Delta values in dBm. The software appends dBm to the values.
  6. Click Start.
    InstrumentStudio creates the calibration file. If Acquisition Phase Aligned was enabled in step 5, InstrumentStudio also creates a Phase Coherent calibration file.
    Note The calibration time will vary depending on the calibration mode and number of calibration points.
  7. Interpret the data:
    • Relative Phase Difference (deg)—This graph shows the channel-to-channel phase difference at discrete points in the instantaneous bandwidth—a snapshot of the performance of the latest completed calibration vector.
    • Relative Amplitude Difference (dB)—This graph shows the channel-to-channel amplitude difference at discrete points in the instantaneous bandwidth—a snapshot of the performance of the latest completed calibration vector.
  8. Click Disconnect.
  9. Reconnect the LO cabling for star configuration for RF recording applications.
    1. Disconnect the SMA to SMA cable from the RF OUT connector on VST_00.
    2. Reconnect the SMA to SMA cable from the CH1: RF OUT connector on the LO Amplifier, as described in Cabling for Analyzer LO Star Configuration.