INFLUENCE OF PHASED-ARRAY ELEMENT SIZE ON BEAM-STEERING BEHAVIOR

Certain characteristics of linear phased arrays were studied by invest igating the influence of element width on the ultrasonic beam steering properties. The beam directivity patterns were analyzed and used as t he criteria for determining optimal transducer design parameters. An a pproximate value of the critical interelement spacing, whilst squelchi ng undesirable grating lobes, was obtained analytically using a Taylor 's series expansion. The effect of element size on the pressure in the steering direction was also studied. This work showed that the influe nce of element size on steering characteristics is marginal and a simp le solution for discrete point sources can be used as a very close app roximation to that of phased arrays. It was recommended to use the lar gest possible element width to produce the highest pressure while supp ressing the grating lobe amplitude. (C) 1998 Elsevier Science B.V. All rights reserved.