In a linear phased array probe, which elements are fired to create each sound beam?

In a linear phased array probe, which elements are fired to create each sound beam?

• A. Only one element
• B. All of the active elements
• C. Every other element
• D. The outermost elements

Answer: (B)

Beam formation in a linear phased array relies on exciting all active elements with precise timing delays. Each element contributes a portion of the radiated wave, and by applying specific delays across the array, those waves sum constructively in a chosen direction to form a single, steerable beam. If only one element fired, the emission would be broad and poorly directed. If only a subset were used—such as alternating elements or just the outermost ones—the effective aperture would shrink and the beam quality would suffer, with wider beam width and higher side lobes. So, each sound beam is produced by firing all of the active elements together, with the appropriate delays, to shape and steer the beam.

Beam formation in a linear phased array relies on exciting all active elements with precise timing delays. Each element contributes a portion of the radiated wave, and by applying specific delays across the array, those waves sum constructively in a chosen direction to form a single, steerable beam. If only one element fired, the emission would be broad and poorly directed. If only a subset were used—such as alternating elements or just the outermost ones—the effective aperture would shrink and the beam quality would suffer, with wider beam width and higher side lobes. So, each sound beam is produced by firing all of the active elements together, with the appropriate delays, to shape and steer the beam.