Which statement best describes a difference between annular and linear phased array transducers?

Which statement best describes a difference between annular and linear phased array transducers?

• A. The linear is steered mechanically
• B. The linear can have multiple focal zones
• C. The annular can create a sector shaped image
• D. The linear has higher pulse repetition frequency

Answer: (C)

An annular array uses concentric circular rings, and beams are formed by delaying each ring’s excitation to focus at a particular depth. Because the rings are circular, the emitted rays fan out around the central axis, producing a wedge or sector-like field of view when the image is formed. This geometric property makes a sector-shaped image a characteristic distinction of annular arrays. Linear phased arrays, with elements in a straight row, create and sweep beams to fill a rectangular field of view. They can be steered electronically and can have multiple focal zones, but their basic image shape is not sector-like the way an annular array’s is. Pulse repetition frequency and steering methods aren’t the defining difference here, so the sector-shaped image best highlights the unique geometry of the annular design.

An annular array uses concentric circular rings, and beams are formed by delaying each ring’s excitation to focus at a particular depth. Because the rings are circular, the emitted rays fan out around the central axis, producing a wedge or sector-like field of view when the image is formed. This geometric property makes a sector-shaped image a characteristic distinction of annular arrays.

Linear phased arrays, with elements in a straight row, create and sweep beams to fill a rectangular field of view. They can be steered electronically and can have multiple focal zones, but their basic image shape is not sector-like the way an annular array’s is. Pulse repetition frequency and steering methods aren’t the defining difference here, so the sector-shaped image best highlights the unique geometry of the annular design.