An investigation of adaptive acquisition techniques for planar near-field antenna measurements

Abstract

This thesis presents an adaptive technique that uses feedback to provide practical information during a planar near-field measurement scan. The feedback is used to decide with certainty when to terminate the planar near-field measurement process. The developed adaptive planar near-field method utilizes a rectangular spiral-type acquisition pattern to acquire the near-field measurements. At the end of each scan iteration, a set of decision functions are rapidly calculated which provide a quality measurement of the resulting far-zone transformation. The decision functions are based on the far-zone radiated patterns, directivity, and the fractional plane wave spectrum error. The decision functions were evaluated using actual planar near-field data set of five different antennas. These experiments have identified those decision functions that are directly related to antenna performance measures and would allow for the termination of the planar near-field test based on a set of relevant stopping conditions.