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Antenna Communication and Metrology Laboratory (ACML)

Researchers in large anechoic chamber with NIST logo on wall looking at robotic arms and equipment.

NIST’s antenna calibration facility features robots that help position the antennas, including those used in 5G systems. This composite photo shows preparations for calibration of a reference antenna (gold horn on the platform under the robotic arm at right) used in research by the 5G mmWave Channel Model Alliance.

Credit: NIST

The ACML, anchored by two six-axis industrial robot arms based on our lab’s pioneering Configurable Robotic MilliMeter-wave Antenna (CROMMA) system, fosters the development of next-generation 5G wireless and spectrum sharing systems through dynamic measurements, flexible scan geometries, and high speeds. Between the newer, dual-robot range and CROMMA, the Antenna Metrology Project tests and characterizes multiple steered-beam and other antennas from ultra-high frequency (UHF, from 300 megahertz through 3 gigahertz) through the 500 gigahertz range.

The details
The ACML’s main anechoic chamber will be a fully shielded, 21-foot-high space that’s 51 feet long by 23 feet wide. In it, one of the two six-axis robots will be on a cart on rails, accommodating antenna separations of up to 10 meters as required for gain extrapolation measurements at “lower” frequencies (the dual-robot system is optimized for the sub-gigahertz to 50 GHz range; CROMMA is optimized for frequencies above 50 GHz).

ACML’s advantages over legacy antenna ranges include configurable geometries, fast and dynamic antenna movement, beam tracking, large payload capacity and improved dynamic accuracy and repeatability. These advantages will become increasingly critical as spectrum use expands to include higher-frequency applications and MIMO systems, which the positional accuracy and scan geometry limitations make difficult to measure. The dual-robot system will support MIMO, phased-array, and other measurements, with an eye on addressing an overarching  need to understand the interference problems created by ever-increasing signal density in frequencies below 50 GHz.

Dual-robot facility specs
   • Shielded anechoic chamber, 51’L x 23’W x 21’H
   • Two robots, 4m vertical reach – 15m horizontal movement.
   • 0.5-60 GHz extrapolation, spherical, cylindrical & planar capabilities
   • Non-static evaluation
      ◦ Rapid extrapolation testing
      ◦ Distance variation
      ◦ Multiple UE/base station testing
      ◦ Rapid spatial variations of UE equipment

CROMMA specs


Created June 9, 2016, Updated August 25, 2022