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Spherical Near-field Measurement System - 20 " ( 0.5 m) max AUT Dimension


The NSI-700S-110 is a Theta/Phi Spherical Near-field Scanner with precision positioners. The system is designed for AUT testing from 10 - 500 GHz. The NSI-700S-110 uses a dual-axis high accuracy stepper motor based positioning system with encoders, allowing for position triggering of the receiver to within 0.005°. The scanner is designed to accommodate mm-Wave up and down converter modules to ensure maximum RF system stability. The mm-Wave modules are exchanged to cover the standard frequency bands from 50 GHz and up, leaving the rack and cabling portion of RF sub-system in intact, making for a very modular and upgradable test system. Both positioners contain integrated RF rotary joints and slip ring assemblies to maximize cable phase stability during testing. The Phi stage (lower) load capacity allows for the integration of microwave probes in order to test antennas on chip, if needed.


The table below shows the maximum AUT sizes that can be tested in spherical near-field mode over the intended band of operation of the system. For cases where the probe to AUT distance (approx. 500 mm) is sufficient to allow for far-field testing, the software allows for far-field measurements to be conducted. Based on the commonly used 2D^2/lambda rule, the maximum AUT size that can be tested in pure far-field mode is also shown the table below:

Frequency [GHz] Wavelength [mm] Largest AUT Dim [mm] for SNF Largest AUT DIM [mm] for FF
10 30.00 400 86
50 6.00 300 39
75 4.00 200 32
110 2.73 136 26
140 2.14 107 23
170 1.76 88 21
220 1.36 68 19
325 0.92 N/A 15
500 0.60 N/A 12

The system interfaces with a wide variety of RF equipment. The system software runs on a dedicated measurement workstation and provides automatic setup of scans based on measurement parameters. Measured data can be processed for far-field or holographic back projection 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 system is delivered fully assembled and aligned to minimize on-site installation effort.

  • Scan Area 360° Phi and 360° in Theta
  • 10 – 500 GHz Measurements (AUT Receive only)
  • Automatic Electronic Alignment Capability (link)
  • Far-field, Holographic and Near-field Patterns

Construction Theta, phi, and pol rotation stages with “L” bracket (aluminum)
Drive System Precision Stepper Motors with encoder feedback
Scan Area 360° Phi and 360° in Theta
Maximum Antenna Load 50 lb (22 kg)
Maximum Antenna Diameter: 20 in (500 mm)
Step Resolution 0.01° Phi and Theta
Position Repeatability 0.005° RMS with encoders
Rotational Speed (Theta and Phi) 30°/s
Power 100-240 VAC switchable, 50/60 Hz, 500 watts

Typical images of NSI-700S-110 Scanner


  • Width - 94 in (2.4 m)
  • Depth - 60 in (1.6 m)
  • Height - 94 in (2.4 m)
  • 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