UCLA´s new bi-polar planar near-field antenna measurement facility

A novel customized bipolar planar near-field antenna measurement technique is presented. The bipolar near-field scanner incorporates an axially rotating test antenna and a rotating probe-carrying arm to sample the near-field on a data grid consisting of concentric circles and radial arcs. This technique offers a large scan plane size with reduced “real estate” requirements and a simple mechanical implementation resulting in a highly accurate and cost-effective antenna measurement and diagnostic system. This paper gives an introduction to the technique and a description of the unique hardware implementation at the University of California, Los Angeles (UCLA). It examines the data processing algorithms that have been developed and customized to exploit the unique features of bipolar planar near-field measurements. Holographic imaging for determination of antenna aperture fields has been incorporated to facilitate antenna diagnostics. Measured results are compared with a far-field range and a plane-rectangular planar near-field range to verify the implementation and validate the method. Excellent agreement was obtained for both the co-polarized and cross-polarized fields