The UCLA bi-polar planar near-field scanner. I. An overview of measured results

The authors describe the UCLA bipolar technique and the associated data processing methods. Measured results are compared with those measured on a conventional far-field range. Some of the salient features of the near-field scanner are: simple mechanical design with no linear motion, uni-structure to eliminate misalignment of axes, probe rotator for despinning probe if desired, use of standard optical bench rotary tables, telescopic antenna pedestal to adjust probe/AUT (antenna under test) spacing, PC control of open-loop stepper motor drive, PC control of HP 8510 with balanced external mixers for low loss and large dynamic range, and large scan plane acquisition for given hardware and chamber. The measured antenna patterns shown demonstrate that this technique yields data commensurate with those measured on the conventional far-field range.<>