With linear phased arrays the spike pattern that is least curved produces the beam with the ______ focus.

With linear phased arrays the spike pattern that is least curved produces the beam with the ______ focus.

• A. Deepest
• B. Shallowest
• C. Narrowest
• D. Wide

Answer: (A)

In a linear phased array, where and how tightly the beam focuses depends on the curvature of the wavefront across the aperture. A spike pattern that is least curved means the wavefront is closest to flat as it leaves the array. A flatter wavefront takes longer to converge to a point, so the focal point sits farther away from the transducer. Hence, the beam achieves its tight focus at a deeper depth. If the spike pattern were more curved, the waves would converge sooner, producing a shallower, nearer focus. The spike pattern here represents the main lobe of the beam, and its curvature directly maps to the depth at which the focus occurs.

In a linear phased array, where and how tightly the beam focuses depends on the curvature of the wavefront across the aperture. A spike pattern that is least curved means the wavefront is closest to flat as it leaves the array. A flatter wavefront takes longer to converge to a point, so the focal point sits farther away from the transducer. Hence, the beam achieves its tight focus at a deeper depth. If the spike pattern were more curved, the waves would converge sooner, producing a shallower, nearer focus. The spike pattern here represents the main lobe of the beam, and its curvature directly maps to the depth at which the focus occurs.