ABSTRACT
The array antenna is composed of a number of individual elements that are arranged in a pre-specified manner with uniform or nonuniform interelement spacing. Design requirements and cost effectiveness often put limitations on the angular resolution capability of an array system. This chapter presents a comparison between the principle of antenna array beamforming based on ultra-wideband (UWB) nonsinusoidal waves and that based on the zero bandwidth, infinitely long, sinusoidal waves. It derives the transfer function and the impulse response of a linear array of sensors receiving impulse-type nonsinusoidal waves. Based on the reciprocity theorem, the transfer function and the impulse response of a passive array of sensors also hold true for an active array of radiators. The synthesized antenna patterns demonstrate desirable directivity and angular resolution characteristics, which make the large-current radiator and the closed-loop receptor very attractive for the implementation of UWB, impulse-type, radar systems.
