Digital delay generator for sonar and radar beam formers

Abstract From the Canadian patent

This invention relates to apparatus and a method of controlling the amount of delay or phase-shift which is applied to a signal received at or transmitted from each transducer in a multi-transducer antenna to produce a beam directed at a specific target point. For each transducer a first look-up table is used for storing first digital words representative of the included angle between the lines joining the target to a reference point and the same, reference point to a transducer. A second look-up table is associated with the first look-up table for each transducer, and stores second digital words representing delay or phase-shift control signals corresponding to ranges of the target …