SwRI expands antenna testing capabilities with spherical near-field range

SAN ANTONIO — July 29, 2025 — Southwest Research Institute (SwRI) is expanding its antenna measurement capabilities with a state-of-the-art spherical near-field antenna range. The 1,260-square-foot indoor range, lined with radio frequency and microwave foam absorbers, is equipped to accurately sample the near field of an antenna. Near-field measurements can be mathematically transformed into far-field data.

“Near field” refers to the complex electromagnetic fields close to the antenna, while the “far field” encompasses the predictable planar waves farther away from the antenna. Analyzing both fields allows a more complete performance evaluation of an antenna under test. Near-field measurements are typically collected in a planar, cylindrical or spherical formation.

“Spherical data collection is the most comprehensive and flexible method of measuring antenna patterns for all antenna types,” said Dr. Jimmy Li, a lead engineer in SwRI’s Defense and Intelligence Solutions Division. “We get the full 3D radiation pattern data for an antenna — not just limited perspectives obtained with other methods.”

Antennas enable the transmission and reception of signals and are the interface between electromagnetic waves and electronic devices. Testing is necessary to evaluate performance and ensure compliance with industry standards and regulations. Antennas are crucial for a wide range of technologies, including cellular networks, Wi-Fi, radar, satellite communications and positioning and navigation systems.

SwRI’s spherical near-field antenna range offers several new advantages, including: