THE BIPOLAR PLANAR NEAR-FIELD MEASUREMENT TECHNIQUE .1. IMPLEMENTATION AND MEASUREMENT COMPARISONS

A novel customized hi-polar planar near-field antenna measurement technique is presented as an alternative to the plane-rectangular and plane-polar measurement techniques. The hi-polar near-field scanner incorporates an axially rotating test antenna and a rotating probe-carrying arm to sample the nearfield on a data grid consisting of concentric circles and radial arcs. This technique offers a targe 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. Part I of this two-part paper gives an introduction to the bi-polar near-field technique and a description of the unique hardware implementation at the University of California, Los Angeles (UCLA). Measured results are compared with those produced by 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. The companion paper gives a complete description of the data processing algorithms customized for the hi-polar technique including near-field to farfield transformation and holographic imaging.