Book: Phased Array Antenna Handbook, Second Edition
Publisher: Artech House Publishers
Phased array antennas consist of multiple stationary antenna elements, which arefed coherently and use variable phase or time-delay control at each element to scana beam to given angles in space. Variable amplitude control is sometimes alsoprovided for pattern shaping. Arrays are sometimes used in place of fixed apertureantennas (reflectors, lenses), because the multiplicity of elements allows more precisecontrol of the radiation pattern, thus resulting in lower sidelobes or carefulpattern shaping. However, the primary reason for using arrays is to produce adirective beam that can be repositioned (scanned) electronically. Although arrayswith fixed (stationary) beams and multiple stationary beams will be discussed in thistext, the primary emphasis will be on those arrays that are scanned electronically.The radar or communication system designer sees the array antenna as acomponent (with measurable input and output) and a set of specifications. Thearray designer sees the details of the array and the physical and electrical limitationsimposed by the radar or communications system, and within those constraintsseeks to optimize the design. This chapter is written from the perspective of, andfor, the system designer. The remainder of the text discusses array design issues.