Spherical near/far field antenna measurement system.

The shielded chamber prevents external interferences while the inner surfaces are covered by RF absorbers offering a working environment as close as possible to free space. External dimensions are 5 m x 3 m x 3m (length x width x height). The operating frequency range is 0.6 to 25.6 GHz.

The roll-over-azimuth positioning system for the antenna under test (AUT) can be moved along a floor slide to adjust the AUT to probe distance between 2.5 and 3 m. The positioning precision of the AUT roll and azimuth axes is of the order of 0.1º and 0.07º, respectively. The dynamic range of the measurements is around 60 dB in the operating band.

The system performs antenna measurements in near and far field. If required, near to far field transformation can be carried out through a software based on the expansion of spherical modes. This algorithm includes probe compensation (pattern and polarization).

The measurement setup also provides a flexible environment suitable to assess the performance of different devices and systems: RCS and radome testing, EMC preliminary testing…