Indoor Over-The-Air (OTA) range is a test environment reproducing free space measurement conditions inside a limited space. This facility is used to fully and accurately characterize device radiation pattern in microwave frequency domain.


The OTA test range solution proposed at CROMA is based on a fully anechoic chamber (non-reflective room) inside a shielded enclosure (Faraday shield), providing a good isolation from any outside signals. The radio-wave absorbing material (pyramidal shape) applied to the walls, ceiling and floor eliminates all possible reflections. The overall dimensions of the chamber ensure the far field conditions (plane wave) over a wide frequency range.

This facility is associated with the following equipments:

– PC based software tool for motion control, data capture, measurement processing and display

– 3 axis positioning system, angular motions (Rx Roll over Azimuth, Tx Roll only)

– Reference dual ridge horn antennas with high directivity

– High performance 4-port Microwave Vector Network Analyzer

– High performance Microwave Spectrum Analyzer and Synthesized Generator.

Characterization capabilities include:

– Antenna VSWR, gain, directivity, beam width and efficiency

– Antenna E plan, H plan, 3D radiation pattern

– Effective Radiated Power measurement

– Transmission and absorption coefficient of metasurfaces.

Technical specifications:

Frequency measurement range: 0.8 – 40GHz (Far Field conditions)

Distance between source antenna and device under test: adjustable up to 3 meters

Device under test maximum weight: up to 1.5kg (low DK Rx mast loading)

Full automatic measurement sequence, on-the-fly data capture for fast cycle

Motion capabilities (all axis): travel range (bidirectional) = 360°, resolution down to 0.1°

Case study:

Such a facility enables users to test easily and accurately their antenna or wireless device in free space, regardless of the environment. Many different testing applications can be conducted with confidence, to check if performance expectations are well achieved.

Access Provider / Facilities