Overview of basic phased array technology theory
Devices using phased arrays are steadily becoming more important in the ultrasonic NDT field compared to when commercial ultrasonic instruments relied entirely on single element transducers that used piezoelectric crystal to generate and receive sound waves.
Phase shifting, or phasing, is in turn a way of controlling constructive and destructive interaction of waves by time-shifting wave fronts that originate from two or more sources. It can be used to bend, steer, or focus the energy of a wave front. Normally, A phased array system is centered around a specialized ultrasonic transducer that contains many individual elements (characteristically from 16 to 256) that can be pulsed separately in a programmed form.