Jan 13 2015
Following two years of design, construction, installation, validation and training, a National Physical Laboratory (NPL) project to install an antenna extrapolation range at the National Institute of Metrology (NIM) in China is finally complete.
The antenna extrapolation range at NIM, China
Extrapolation ranges provide the high accuracy antenna standards essential for applications such as satellite communications and Earth remote sensing. Since opening a new campus in Changping, north-west Beijing, NIM has been keen to improve their microwave antenna measurement facilities through collaboration with NPL.
Over the course of the project, the NPL team made multiple site visits, produced over 300 design drawings, and manufactured and tested hundreds of parts. In addition to the hardware supplied, the project also included the provision of software, procedures, validation and training.
The extrapolation range is a chamber lined with radiation absorbing material in the form of foam pyramids, loaded with carbon particles. This forms an essentially reflection-free environment in which to test microwave antennas. The measurement system comprises a computer-controlled carriage that moves on a precision rail guidance system to vary the separation between the antennas, while recording the received power. The data obtained can then be processed to obtain the gain and polarisation properties of the antenna under test.
The equipment was shipped to China in January, and, following installation by NPL's Engineering Services, the newly-completed extrapolation range is producing excellent results. The performance of the precision rails, an essential part of the extrapolation range, is much better than expected, leading to very low uncertainties in antenna parameter measurement, along with optimized system configuration.
NIM attached great importance to the project, and many directors and experts from government, research institutes, universities and industry have been invited to visit the new facility. Every visitor highly praised the collaborative achievement. "The extrapolation range greatly improves China's national microwave measurement standards, and is a new highlight in NIM infrastructure construction," said Mr Wu Fan, Director of the Division of Electronics and Information Technology at NIM.
It is hoped that the delivery of the extrapolation range project marks the start of a fruitful partnership between NPL and NIM, and a symposium to promote future collaboration between the two institutes is currently being planned for April 2015.