Digital Array Phasing

Abstract

The extension of digital techniques to the problem of processing the output of an array of point receiving elements in an acoustic field has given rise to a method of phasing called DIMUS (Digital Multi-beam Steering). This digital technique incorporates the use of shift registers as delay line elements which results in a number of operational advantages. A description of the DIMUS technique is given. The effects of amplitude and time quantization imposed by the digital circuits are considered in the light of the relative signal processing gain of the array referred to an exact analog phasing network. The processing gain is computed as a function of sampling frequency for a number of types of signals. [This work represents one of the results of research carried out under Contract Nonr 2216 (10) with the Office of Naval Research.]