ABSTRACT
An array antenna is a structure composed of a collection of individual radiation elements, each excited with a specific amplitude and phase, whose electromagnetic fields are spatially combined to realize a specific radiation pattern, usually in the far field. An array antenna can also be thought of as a continuous aperture distribution that is sampled at discrete locations within the aperture. A phased array antenna [1-4] is an array whose main beam can be electrically steered in one or more dimensions by changing the excitation phases on the individual radiation elements of the array. Beam scanning rates on the order of 1 µs are possible for certain array architectures, which is orders of magnitude more rapid than stateof-the-art mechanical scanning with motor technology. Rapid beam scanning is crucial in fire control and other radar systems where wide scan volumes must be rapidly interrogated and where multiple target tracking is a requirement.
