This single volume provides a comprehensive introduction and explanation of both the theory and practice of 'Planar Near-Field Antenna Measurements' from its basic postulates and assumptions, to the intricacies of its deployment in complex and demanding measurement scenarios. To do this the book initially examines the properties of antennas that allow them to enhance the free space interaction of electronic systems and this leads into a full description of the theory of 'Planar Near-Field Scanning'.The utility of the planar methodology is illustrated with example measurement campaigns that include discussion of the characterisation of a wide range of antennas. Advanced techniques, including back transforms and poly-planar scan techniques, plus error assessment and correction, are examined and explained along with an extensive review of data assessment methodologies.