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Configurable Robotic MilliMeter-wave Antenna (CROMMA)

Configurable Robotic MilliMeter-wave Antenna (CROMMA)

Configurable Robotic MilliMeter-wave Antenna (CROMMA)

The big picture
The CTL Antenna Metrology Project’s Antenna Configurable Robotic MilliMeter-wave Antenna facility (CROMMA) is dedicated to extending NIST-developed near-field scanning techniques to antenna technologies from 50 GHz up to 500 GHz. CROMMA, the world’s first robotic arm for antenna measurement, was developed by NIST and is part of CTL’s Robotically Enhanced Antenna Laboratory for Metrology (REALM).  CROMMA enables measurement and characterization of very-high-frequency massive MIMO, phased array and quasi-optical systems expected  to find wide use in next-generation 5G wireless systems.

NIST is working with leaders in the aerospace, wireless and other industries to transfer the technologies behind CROMMA for commercial use.

The details
   • Accurate near-field measurements
      ◦ Demonstrated spherical pattern measurements at 183 GHz with λ/60 accuracy
      ◦ Ability to place the probe in six degrees of freedom (DoF) relative to the robot face allows for accurate positioning (geometry creation) and rotation for polarization changing
      ◦ Easily accommodates offset probes
      ◦ Localized scans around areas of interest (multi-antenna platforms)
   • High speed, enabling fast near-field testing
      ◦ Rapid real-time testing of moving targets (UE/RCS) against fixed assets (base-stations/radar/comm)
      ◦ Minimal, real-time tests for multi-beam near-field testing
      ◦ Rapid perturbation testing of UE/eNB links
   • Non-antenna applications
      ◦ Medical/security/imaging scanning
      ◦ EMI testing / localization
   • Scalable
      ◦ Add multiple robots to simulate complex environments.
      ◦ COTS software to design test paths and prevent robot collisions

CROMMA specs
   • Probe/UE - 6-axis COTS robot
      ◦ Horizontal ~2.5m radius
      ◦ Vertical ~4 m top/bottom
      ◦ 35 Kg payload
      ◦ 0.07mm repeatability @ 60 km/hour
      ◦ Positional accuracy to 25 microns
   • AUT/eNB/Source mounting
      ◦ 0.0001º ϕ rotator
      ◦ 30 Kg hexapod for AUT alignment
      ◦ Larger payload/lower cost COTS options
   • Laser Tracker
      ◦ Provides 3 DoF and 6 DoF probe & AUT position with accuracy to 25 microns
      ◦ 4 KHz update rate
      ◦ Only needed for periodic calibration for operation below ~60 GHz
   • Validated scan geometries
      ◦ Spherical and extrapolation
      ◦ Planar and cylindrical under development

Created June 9, 2016, Updated January 30, 2024