title: Analysis of resolution for an amplitude-steered array
abstract: In 1976, Hughes and Thompson introduced the idea of steering the maximum response of a linear array by amplitude weighting the output signals of the elements, thus eliminating the need for time delays or phase-shift networks. Currently that amplitude-steered array concept is being extended to a broadband two-dimensional array that can be used for real-time three-dimensional imaging. In shifting the use of the amplitude-steered array from underwater acoustic communications to imaging, we must consider different issues of the array's performance such as lateral and axial resolution. For the linear amplitude-steered array, we show that both lateral and axial resolution are limited by the length of the array. The dependence of axial resolution on the length of the array is a unique feature of the amplitude-steered array, leading to an interesting tradeoff between lateral and axial resolution. A theoretical basis for the dependence is developed and simulation results are given.
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana 61801, USA. hillsley@uiuc.edu
authors.initials: CH
authors.lastname: Frazier
authors.initials: WJ
authors.lastname: Hughes
authors.initials: WD
authors.lastname: O'Brien