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Near-Field Systems: Precision, Performance, and Proven Expertise
We are proud to be pioneers in near-field technology, with our first commercial near-field systems delivered more than 45 years ago. We offer a wide range of near-field system types and sizes to address your high throughput production or R&D testing needs. Whether you’re looking to test a low frequency omnidirectional antenna, or a high frequency phased array, we’ve got you covered. Our team of experts in the field will work closely with you to select and optimize the right solution that meets and exceeds your requirements. Trust the experts at NSI-MI Technologies to provide you with reliable and accurate results for all your antenna measurement needs.
Near-field measurements rely on synthetic aperture techniques. This means that data collection is not real-time, and care must be taken to ensure that the majority of radiated energy is collected by the near-field probe to guarantee an accurate transformation to far-field. Learn more about our line of near-field measurement systems below, along with some guidelines for selecting the right system based on your needs.
Near-field systems offer many unique benefits to their far-field counterparts
Antenna pattern characterization at greatly reduced range length
Most efficient use of real estate
Thermally controlled environment
Better access to AUT
Highly repeatable measurements
Superior cross-polar performance
Planar Near-Field Systems
Learn MoreCourtesy of STFC RAL Space
PNF systems are ideally suited for characterizing medium and high gain antennas accurately and efficiently. A key benefit of the PNF geometry is that the DUT remains stationary during test. This is especially important for modern antennas whose complexity makes dynamic motion during test challenging. This is the industry standard solution for calibrating Active Electronically Scanned Arrays (AESA) using the park & probe technique.
We recommend limiting PNF testing to antennas whose gain is greater than or equal to ~15 dBi, with data collection limited to ~±80º from DUT boresight. For increased versatility, Spherical (SNF) and Cylindrical (CNF) add-on options are available for some PNF types. These combination systems give you the efficiency of a PNF solution combined with the flexibility to characterize a wider range of antenna types.
NSI-MI offers a wide range of PNF system types:
Vertical PNF
The most common PNF type, suitable for most antennas whose apertures can be installed vertically for test.
Horizontal PNF
Excellent choice for high-throughput production testing, gravitationally sensitive antennas, or facilities with ceiling height restrictions.
Spherical Near-Field Systems
Learn MoreSNF systems are widely considered to be amongst the most accurate solutions available to measure full sphere radiation patterns. The SNF method was first pioneered by the Technical University of Denmark, who are still considered world experts to this day. NSI-MI delivered our first commercial SNF test system in 1980 and have been pushing the state-of-the-art ever since.
While SNF solutions are generally less efficient than the PNF counterpart, the ability to characterize all or most of the radiation pattern in a controlled environment is unparalleled. The SNF geometry has been used to measure all types of antennas, including many complex antennas for defense and space applications.
NSI-MI’s line of SNF test systems includes several options designed to solve the most demanding of measurement challenges:
Roll over Azimuth
This versatile solution, the most common SNF implementation, offers wide frequency coverage and is capable of measuring a full sphere for antennas up to 3 meters in diameter. An optional mast can be used for cellular and PCS-band base station antenna testing.
Overhead Theta Axis
Spherical scanning is accomplished by rotating the antenna-under-test (AUT) on an azimuth positioning system while elevation scans are accomplished using a near-field probe mounted to an arch or rotating gantry.
Stationary SNF
An ideal solution for measuring radiation characteristics of unmoving antennas that do not require full spherical coverage and cannot be tested using the planar near-field technique.
Cylindrical Near-Field Systems
Learn MoreCylindrical Near-Field (CNF) method offers the ability to acquire data over a vertical cylinder surrounding the DUT. This type of system offers superior angular coverage than the PNF geometry but does not offer full sphere coverage like the SNF approach. CNF is well-suited to testing fan beam antennas, or to measure the backlobes of antennas. Care must be taken to ensure that minimal radiation is directed toward the open top and bottom of the cylinder.
CNF
A vertical CNF system combines a lower Azimuth rotator with a vertical linear axis. Since a PNF scanner already includes such a linear axis, CNF upgrades to vertical PNF systems are common.
Robotic Systems
Learn MoreNSI-MI Technologiesʼ 8-Axis robotic antenna measurement system (RAMS) is ideal for measuring antennas up to 2.4 m x 1.2 m (8 ft x 4 ft). It is well suited to perform testing of high, medium, and low gain antennas, since it offers planar near-field, cylindrical near-field, and spherical near-field capabilities.
Robot
The NSI-MI Technologies 8-Axis RAMS is a versatile antenna measurement system that uses a 6-axis robotic arm and precision positioners to perform planar, cylindrical, and spherical near-field testing on antennas up to 2.4 m x 1.2 m.
Pre-Configured Systems
Learn MoreIf accelerated delivery schedules or budget constraints are driving your purchasing decision for an RF measurement testing solution, we offer economical, pre-engineered systems suitable for most applications and testing needs. Our turnkey solutions are designed for straightforward assembly in either an anechoic chamber or open facility, depending on the type of system and test application.
Pre-Configured Systems
We offer both SNF and PNF pre-configured systems supporting frequency ranges from 0.4 to 110 GHz. Various options and accessories are available to maximize the throughput and flexibility of your range.