In a phased-array transducer, what happens if element delays are mismatched?

• A. Decreased bandwidth only
• B. Steering errors and artifacts
• C. No effect
• D. Improved focusing

Answer: (B)

Timing alignment across array elements controls where the beam goes and where it focuses. When delays are mismatched, the waves from different elements don’t arrive in phase at the intended direction and depth. The result is that the beam tilts away from the planned steering angle and the focal region becomes smeared or shifted. This creates visible artifacts in the image, along with reduced lateral resolution due to a broader main lobe and increased energy in unwanted directions (side and grating lobes). Bandwidth isn’t the primary change here—the issue is how energy is distributed spatially because the phase relationships are off. So the dominant outcome is steering errors and artifacts.