Which transducer type is commonly used to enable electronic steering and dynamic focusing of the beam?

• A. Linear array
• B. Convex array
• C. Annular array
• D. Phased array

Answer: (D)

Electronic steering and dynamic focusing rely on beamforming across multiple elements. In a phased array, each element is driven with a specific time delay (or phase shift). By tailoring these delays, the beams can be aimed at different angles without moving the transducer, achieving electronic steering. At the same time, adjusting the delays for different depths focuses the beam at varying ranges, giving dynamic focusing. Other transducer types have fixed geometries and rely on mechanical movement or fixed focal patterns, so they don’t offer the rapid, flexible electronic steering and depth-dependent focusing that a phased array provides.