Which array type uses circular rings with a common center to form its geometry?

Which array type uses circular rings with a common center to form its geometry?

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

Answer: (D)

The arrangement being tested is about how ultrasound transducer elements are laid out to shape the beam. An annular array uses circular rings that share a common center, forming concentric rings around a single focal point. This circular aperture lets the system focus the beam by applying different time delays to each ring, enabling strong lateral resolution at specific depths. This is different from other array types: a phased or linear array uses elements in a straight line and relies on delays across those elements to steer and focus, while a curvilinear array arranges elements along a curved path rather than in concentric rings. The defining feature here—circular rings with a common center—points to the annular array.

The arrangement being tested is about how ultrasound transducer elements are laid out to shape the beam. An annular array uses circular rings that share a common center, forming concentric rings around a single focal point. This circular aperture lets the system focus the beam by applying different time delays to each ring, enabling strong lateral resolution at specific depths.

This is different from other array types: a phased or linear array uses elements in a straight line and relies on delays across those elements to steer and focus, while a curvilinear array arranges elements along a curved path rather than in concentric rings. The defining feature here—circular rings with a common center—points to the annular array.