The Roll over Azimuth solution is the most common system type for the characterization of full sphere radiation patterns in the near-field. The DUT mounts to a roll-over-azimuth positioner assembly, enabling rotation around two orthogonal axes to measure antennas with up to 3 m (10 ft) diameter from 200 MHz to 110 GHz and beyond, depending on the chosen model. This system can serve as a dual-purpose SNF and direct illumination far-field range and is often installed as an add-on to a Vertical Planar Near-field (PNF-XYV) system.

This system type offers the unique benefit of being the only SNF geometry capable of measuring the entire radiation pattern, often within facilities with height restrictions. This is balanced by the fact that the SNF-RAZ requires the antenna to be mounted horizontally, meaning that it will experience a changing gravity vector during measurements. Learn more about our line of Roll over Azimuth systems below.

The Overhead Theta Axis system is ideal for measuring medium and low gain vertically oriented antennas up to 7.3 m (24 ft) in diameter. The DUT mounts to a lower azimuth stage, while a probe moves along a fixed arch or moving gantry to generate a partial sphere around the DUT. This system type reduces the gravitational sensitivities observed with the more common Roll over Azimuth geometry. This implementation also has the added benefit of greatly simplifying the challenges associated with cable management since cabling to the DUT only needs to pass through a single rotary axis.

The maximum achievable angular coverage depends on the size of the DUT, the available room height, and the lowest test frequency. For most applications, NSI-MI recommends the Swing Arm over Azimuth (gantry-style) system, but the more precise Arch over Azimuth solution is available for the most mechanically demanding requirements. Learn more about our line of Overhead Theta Axis systems below.

NSI-MI offers several Stationary Spherical Near-Field Solutions to address some special cases where a DUT cannot be moved during measurement. These include many millimeter wave and sub-millimeter wave on-chip antennas excited using probing stations and active phased arrays with too many control, RF and coolant lines to manage on a conventional SNF system. These systems support measurements from 1 GHz up to 330 GHz and beyond, depending on the chosen model.

Various models are available, each optimized for a particular class of antennas and application. The selection of the ideal Stationary SNF system will depend on the size of your DUT, the operating frequency, and desired mounting orientation. Learn more about our Stationary Spherical Near-Field Solutions below.