Which method is used to steer the beam across the aperture by adjusting element timing?

• A. Apodization
• B. Phased-array steering
• C. Dynamic receive focusing
• D. Mechanical focusing

Answer: (B)

Electronic beam steering is achieved by applying time delays to the elements of a phased array to tilt the wavefront and steer the beam across the aperture. By introducing a progressive delay from one side of the array to the other, the emitted waves interfere constructively at an angle, bending the main beam without moving the transducer. The steering angle is set by the gradient of those delays relative to the wavelength.

Other approaches don’t accomplish this lateral steering in the same way. Apodization adjusts each element’s amplitude to shape the beam and reduce sidelobes, but it doesn’t shift the beam direction. Dynamic receive focusing uses delays to focus at different depths during reception, not to steer the transmit beam across the aperture. Mechanical focusing relies on physical curvature or moving parts to change direction, not electronic timing adjustments.