The highly directive beams attainable with microwave antennas have been utilized to achieve large antenna gain, precision direction finding, and a high degree of resolution of complex targets. The exploration of a wide angular region with such sharp beams requires an involved scanning operation in which the scanning time becomes a limiting factor. This problem is much simplified if the required scanning can be reduced to only one direction, the coverage of the angular region being completed by fanning the beam broadly. The purpose of this chapter is to describe several applications for shaped beams, to discuss requirements imposed on the beam by these applications, and to present a number of design techniques for producing shaped-beam antennas.