Table Of Contents

Aligning the Reference and Measurement Antennas

Version:
Last Modified: February 23, 2021

Content applies to the DFF chamber.

Antenna alignment improves the repeatability and accuracy of your test. The reference antenna (p/n 754960-01) data assumes that the antennas are perfectly aligned, so alignment must be performed for each antenna setup.

Figure 1. Reference Antenna Pointing Misalignment

To minimize the measurement uncertainty introduced by improper antenna alignment, complete the following steps before performing system calibration.

spd-note-caution
Caution  

DO NOT STARE INTO THE BEAM. Staring directly into the beam or the reflected beam can cause permanent eye damage. The lasers, which users can power on when performing the alignment, are class 2 (Class II) laser products and have visible laser radiation. Users are instructed not to stare into the beam, and should perform active protective reactions by moving the head or closing the eyes and to avoid continued intentional intrabeam viewing. The laser products are used as alignment lasers only, per CFR Title 21, Chapter I, Subchapter J, Part 1040.11(b). Adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure. The laser products comply with the regulation of EN 60825-1 and BGV B2 for Class 2 laser. The customer is responsible for ensuring that the device conforms to the laser standard.

spd-note-caution
Attention  

NE PAS REGARDER FIXEMENT LE FAISCEAU. Fixer directement le faisceau ou le faisceau réfléchi peut causer des lésions oculaires permanentes. Les lasers, que les utilisateurs peuvent allumer lorsqu'ils effectuent l'alignement, sont des produits laser de classe 2 (classe II) et ont un rayonnement laser visible. Les utilisateurs ont pour consigne de ne pas regarder fixement le faisceau et doivent réagir de façon active pour se protéger, en bougeant la tête ou en fermant les yeux, et éviter de regarder intentionnellement le faisceau de façon continue. Les produits laser sont utilisés uniquement comme lasers d'alignement, conformément au Titre 21 du CFR, chapitre I, sous-chapitre J, partie 1040.11 (b). Les ajustements ou l'exécution de procédures autres que celles spécifiées ici peuvent entraîner une exposition à des rayonnements dangereux. Les produits laser respectent les réglementations EN 60825-1 et BGV B2 pour les lasers de classe 2. Le client doit s'assurer que l'appareil est conforme aux normes concernant les lasers.

  1. Launch the mmWave OTA Validation Positioner Control Panel.
  2. Set the Elevation near -90° to rotate the positioner so the reference antenna (p/n 754960-01) points straight up toward the measurement antenna (p/n 754959-01), then set the Azimuth so the arrow on the positioner rotor points to 0 on the positioner dial scale, as shown in Attaching the Reference Antenna.
  3. Attach the calibration laser to the laser alignment fixture and plug the laser USB cable into the USB port inside the chamber.
  4. Secure the laser alignment fixture to the measurement antenna fixture using an Allen wrench to tighten the screws and alignment pins on the fixture.
    Figure 2. Laser Alignment Fixture Components
    1. Allen Screw
    2. Laser Alignment Fixture
    3. Calibration Laser
  5. Use the alignment knobs on the measurement antenna fixture to move the measurement antenna (p/n 754959-01) horizontally and vertically until the laser cross hits the center of the reference antenna (p/n 754960-01). When the laser cross hits the center of the reference antenna (p/n 754960-01), the measurement antenna (p/n 754959-01) is aligned.
  6. Attach the reference antenna (p/n 754960-01) laser to the reference antenna fixture and plug the reference antenna laser USB cable into the USB port inside the chamber.
  7. Use the mmWave OTA Validation Positioner Control Panel to move the laser until it is aligned to the center of the cross marker on the measurement antenna fixture.
  8. When the laser cross hits the center of the cross marker, add 90° to the current Elevation number and click the Set Absolute Home button on the Settings tab in the mmWave OTA Validation Positioner Control Panel. The position is saved in the chamber and remains after restarting the system.
  9. Unplug the calibration laser USB cable from the USB port.
  10. Remove the laser alignment fixture from the measurement antenna fixture.
After antenna alignment is complete, you can perform system calibration and determine all the path losses in the system.

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