Table Of Contents

Performing System Calibration in RF-RF Mode

Version:
    Last Modified: February 23, 2021

    (Chamber revB) Before you begin, verify that the LED status indicator on the chamber exterior is solid green.
    1. Connect the power meter USB cable to the PXI chassis USB port.
    2. Open the RF System Calibration Assistant and click Start Calibration.
    3. In the Load Configuration Dialog box, browse to <NIDocDir>\OTA Test\System Calibration Files.
    4. Select OTA-Test-Cal-Base.cfg and click Open.
      spd-note-note
      Note  

      During the calibration configuration process, the default name of the PXIe-3622 in Measurement & Automation Explorer (MAX) is mmWave_VST.

    5. Select Use existing calibration configuration. The NI RF System Calibration Assistant Configurator window launches.
    6. In the Resources window, verify that all resources and resource settings are correct for the path loss characterization as shown in the following figure. Ensure the resource name for the power meter matches the name used in MAX.
      Figure 1. Resources Window

      By default, Self Calibrate Analyzer and Self Calibrate Generator are not selected. NI recommends that you follow the calibration recommendations in the PXIe-5831 Specifications document to perform self-calibration when the best accuracy numbers are desired.

      spd-note-note
      Note  

      NI recommends not changing the default location of calibration files in the File Resources section.

    7. Click Next.
    8. In the (De-)Embedding Resources window, verify that Resource Name and Resource Type are correct for the reference antenna (p/n 754960-01).
      Figure 2. (De-)Embedding Resources Window
    9. In the Option String field, verify that the following string appears: Interpolate=true,FilePath=<antenna data XML file path>,PathName=VGain, where <antenna data XML file path> is the location of the reference antenna values XML file.
      spd-note-note
      Note  

      If you do not have the XML file, contact NI. The calibration values are part of the reference antenna calibration data and are accessible through the embedded QR code on the antenna. The gain values are converted into an XML file that the software can read.

    10. To accept all calibration settings, click Calibrate.
      spd-note-note
      Note  

      Refer to Advanced System Calibration Settings for more information about configuring advanced settings.

    11. When the Connect Power Meter Dialog box appears, complete the following steps:
      1. Disconnect the 2.4 mm (m)-to-2.4 mm (m) cable (p/n 769753-1219) from the reference antenna (p/n 754960-01) and connect it to the power meter.
      2. Follow the onscreen prompts to connect correct cables and then click Continue.
      3. When the calibration is complete, review the graphs and values to ensure the results are as expected. Click Accept Values or repeat the calibration if necessary.
      4. (Optional) For the second signal generator path, disconnect the 2.4 mm (m)-to-2.4 mm (m) cable (p/n 769753-1219) from the power meter. Connect the opposite end of the second 2.4 mm (m)-to-2.4 mm (m) cable (p/n 769753-1219) connected to the interior chamber rear bulkhead 2A port[1] to the power meter. Then repeat steps 11b-11c.
    12. When the Connect VSA Dialog box appears, complete the following steps:
      1. Disconnect the power meter from all cables.
      2. Reconnect the opposite end of the 2.4 mm (m)-to-2.4 mm (m) cable (p/n 769753-1219) to the reference antenna (p/n 754960-01).
      3. In the mmWave OTA Validation Positioner Control Panel, set Azimuth to 90° and Elevation to -90° to rotate the antenna as shown in the following figure. The calibration laser fixture faces the chamber door and the laser points up toward the measurement antenna (p/n 754959-01).
      4. Click Continue.
    13. When the MeasAntennaV dialog box appears, set Azimuth to in the mmWave OTA Validation Positioner Control Panel to rotate the antenna as shown in the following figure, then continue with calibration. This ensures that the correct polarization is measured.

      Once the signal analyzer and signal generator paths are complete, the Calibration Complete window appears with the file locations of the path loss results.

      spd-note-tip
      Tip  

      If you do not want to receive an error or use a calibration file, leave the Calibration Path field in the mmWave OTA Validation Configurator empty.

    • 1 If you use CATR chamber revA, connect the opposite end of the second 2.4 mm (m)-to-2.4 mm (m) cable (p/n 769753-1219) connected to the interior chamber rear bulkhead 2B port using a 2.92 mm (m)-to-2.4 mm (f) adapter (p/n 755384-01) to the power meter.

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