Patent ID: 7227813

Claim:
A method for forming a plurality of beams from a reflected signal received by a transducer array having first and second receiver elements, each of said first and second receiver elements receiving the reflected signal at a phase dependent upon the position of the first receiver element relative to the second, the received signal at each of the first and second receiver elements being sampled and converted to a digital signal by first and second associated analog-to-digital converters at a sampling rate defining a time interval during which a first value representing the amplitude of the received signal at the first receiver element and a second value representing the amplitude of the received signal at the second receiver are available during said time interval, comprising the steps of: (a) applying a first weighting factor to the first value during a first portion of the time interval to generate a first resultant for a first beam for the first receiver element; (b) applying a second weighting factor to the first value during a second portion of the time interval to generate a second resultant for a second beam for the first receiver element; (c) applying a third weighting factor to the second value during a third portion of the time interval to generate a third resultant for a first beam for the second receiver element; (d) applying a fourth weighing factor to the second value during a fourth portion of the time interval to generate a fourth resultant for a second beam for the second receiver element; (e) combining the first and third resultants to generate the first beam; and (f) combining the second and fourth resultants to generate the second beam.