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Spherical Near-field Measurement System - 288" (7.3 m) max AUT Dimension



The NSI-700S-171 scanner is an ideal system for measuring medium and low gain antennas up to 288 inches (7.3 m) in diameter. It is also well suited to perform testing of stand-alone antennas that fit inside this dimensional envelope. The NSI-700S-171 uses a dual-axis Theta-over-Phi high accuracy positioning system. The Phi positioner supporting the AUT (Antenna Under Test) is an NSI-SC-8007 and the Theta positioner that rotates the swing arm is an NSI-SC-8005. The system can support AUT loads of up to 60,000 lb (27,216 kg). The NSI-700S-171 uses an NSI-SC-5631 rotation stage to change probe polarization when needed. This system offers the ideal solution for characterization of radiation in the upper hemisphere of the AUT suspended above a fully absorber lined floor.


The system interfaces with a wide variety of RF equipment and is capable of measuring amplitude and phase patterns from 370 MHz to 20 GHz. The system software runs on an Intel based measurement workstation and provides 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 scanner is controlled by the NSI-SC-5915 Panther motion controller, allowing for continuous Phi axis rotation during testing as well as precision triggering of the RF sub-system based on positioner encoder feedback. The positioner controller also allows for simultaneous motion of axes (if required) and full angular structure correction to compensate for gravitational deformation of the swing arm.

  • Scan Area 360° Phi and +/- 120° (or optionally greater) in Theta
  • 370 MHz to 20 GHz
  • High accuracy positioners
  • Low maintenance
  • Easy upgrade in frequency
  • Automatic electronic alignment capability (link)
  • Complete 3D characterization
  • Far-field, Holographic and Near-field patterns
  • Optional dual-port probes, 400 MHz to 18 GHz
  • Far-field measurement options available

Construction Theta, Phi, and Pol rotation stages with aluminum overhead swing arm, steel support tower, steel vertical arm
Drive System Precision Stepper Motors
Scan Area 360° Phi and +/- 120° (or optionally greater) in Theta
Maximum Antenna Load 60,000 lb (27,216 kg)
Maximum Antenna Diameter: 288 in (7.3 m)
Resolution 0.0007° Phi and Theta
Position Repeatability 0.015° RMS
Rotational Speed (Theta and Phi) 20°/s Phi, 10 °/s Theta
System Controller NSI controller with serial and parallel I/O interfaces
Measurement Workstation Measurement workstation computer with large LCD monitor
Stepper Motor Power Amplifier EIA 19” rack mount. (7” high x 14” deep)
Motor Cables Quick-connect
Scanner Absorber Absorber Kit (12” pyramidal cone), Flat
Probe Open-ended Waveguide Probe(s) or optional broadband single or dual pol probe antennas
RF Cables 20 GHz RF Cables
Rotary Joints Qty. 3 - DC-26.5 GHz, (Phi, Theta, Pol)
Supported RF Devices NSI Panther Receiver Subsystem or selection of Keysight, Rohde & Schwarz and Anritsu VNA's (contact NSI for a complete list)
Power 100-240 VAC switchable, 50/60 Hz, 500 watts

400MHz reference antenna being tested on NSI-700S-171 Spherical System with a dual pol probe


  • Width - 371 in (9.4 m)
  • Depth - 201 in (5.1 m)
  • Height - 276 in (7.0 m)
  • Weight - approx. 6,800 lb (3,085 kg)

  • No additional links are currently available.

Please contact the NSI Sales department to order this product.

Nearfield Systems, Incorporated
19730 Magellan Drive, Torrance, CA 90502, USA, Tel: 310.525.7000, Fax: 310.525.7100
Email: sales@nearfield.com. Visit our website: www.nearfield.com