Adaptive antennas are integral parts of ground-based, airborne, and spaceborne communication systems, as well as radar systems that must function in the presence of jamming and other sources of interference. Based on the author's extensive research at MIT Lincoln Laboratory, this authoritative resource offers antenna, communications and radar engineers an in-depth description of adaptive antenna and phased array design, emphasizing RF characteristics and field testing methods. For the first time in any book, practitioners find proven techniques and design guidance on specialized types of arrays, using monopole radiating elements, slotted cylinders and ultrawideband dipoles. Moreover, this unique book describes a novel focused near-field technique that helps engineers measure performance of large aperture radar systems and communications systems.