True time-delay beam forming using acousto-optics

Abstract

Wide aperture arrays for transmitting and receiving wideband signals suffer beam broadening when steered away from array normal with phase delays between the array elements. This beam dispersion is eliminated if the signal is time delayed between antenna array elements. This paper describes an acoustooptic signal processing architecture that generates and controls, with the frequency of a single signal, a set of the time delays required for linear antenna array beam forming. This acousto-optic architecture allows an array to scan a beam rapidly over a continuum of angles. Results of analysis are presented showing that a narrow beam can be formed and maintained as it is scanned over a wide range of angles.