National Physical Laboratory

Mobile Phone Base-Station Antennas

NPL measures the radiation performance of Mobile Phone Base-Station Antennas in its Spherical Near-Field Range.

NPL Positioner SystemFigure 1: The NPL Positioner System 

The Spherical Near-Field Range is housed within a fully screened, 15 m by 7.5 m by 7.5 m, anechoic chamber. The chamber is temperature controlled to 23 ±1 deg C and it operates from 0.5 GHz to 110 GHz.

The antenna is mounted on an azimuth over elevation positioner system for a 1.2 m long antenna. Access to the entire radiation pattern of the antenna is very good apart from a small amount of blockage in the downward direction. Due to the spherical transform process, all parameters are measured in the true far-field of the antenna, independent of its size. Antennas up to typically 2.5 m long can be accommodated.

NPL can measure all of the standard parameter of the antenna, including:

  • True and Realised Gain
  • Directivity
  • Vertical and Horizontal Co- and Cross-Polar Radiation Patterns
  • Horizontal Beamwidth
  • Elevation Beamwidth
  • Beam Pointing
  • Front-to-Back Ratio
  • Upper Sidelobe Suppression
  • Null Fill
  • Boresight Crosspolar Ratio
  • Reflection Coefficient
  • Power Handling
  • Inter- and Intra-Band Port-to-Port Isolation

As the measurements are carried out indoors they can be made regardless of the weather. The repeatability of the facility is excellent, allowing very accurate comparisons between the performances of different antennas to be made.

The results are supplied in Excel Spreadsheets, allowing the customer to further manipulate the data as required.

NPL can also measure the coupling between base station antennas to enable the interference between co-located antennas to be assessed.


Customer Service tel: +44 20 8943 6796

Last Updated: 25 Mar 2010
Created: 17 Apr 2009


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