NSI-MI Technologies' Spherical Near-Field Arch Measurement System, SNF-ARCV-2.4, is an ideal solution for measuring radiation characteristics of non-moving antennas that do not require full spherical coverage and cannot be tested using the planar near-field technique. Three axes of motion revolve around the stationary AUT and an arch frame continuously rotates in the phi axis at speeds up to 12 revolutions per minute. The theta axis carriage carries the measurement probe through 115 degrees of travel along the arch frame, with a linear slide providing precise real time radial adjustment. Proprietary error correction technique is used to further enhance its global accuracy. The versatile system is suitable for advanced phased array and general-purpose antenna testing.“

The testing of these large digital phased arrays presents some unique challenges. These typically include keeping the Antenna Under Test (AUT) stationary during testing and contending with very high digital data rates. The need to keep the AUT stationary can be driven by aspects like the complexity of cabling or cooling systems, minimizing facility high power absorber usage, or the desire to minimize risk to the hardware. Although this can be achieved readily by using a planar near-field test approach, low directivity elements and the need to test these as individual radiators often preclude that solution and dictates a spherical near-field (SNF) test system like the SNF-ARCV-2.4,” says Daniël Janse van Rensburg, Senior Vice President and Chief Technology Officer of NSI-MI Technologies and Far-Field Systems.

The Spherical Near-Field Vertical Arch Measurement System supports NSI-MI, Keysight, and Rohde & Schwarz RF receivers and is capable of measuring amplitude and phase patterns from low frequency to mmWave. The system includes a software workstation preloaded with NSI2000 antenna measurement software and Windows operating system, providing automatic setup of scans based on measurement parameters and desired output. Measured data can be processed for far-field or holographic patterns yielding complete characterization of the antenna’s performance. A single data set provides information on antenna gain, side lobe structure, beam pointing and cross polarization.

The SNF-ARCV-2.4 is useful for typical applications such as wireless technology, general antenna testing, and satellite antenna testing.

Key Features
  • Radiation pattern testing of stationary AUT
  • High positioning accuracy and repeatability
  • Rotary positioner provides 360° phi rotation of arch
  • Automatic electronic alignment capability
  • 3D dynamic on-the-fly probe position correction
  • Multi-beam, multi-frequency control of RF subsystem
  • Accurate probe motion from 0–115° in theta

More information about the Spherical Near-Field Vertical Arch Measurement System is available at www.nsi-mi.com