In convex array operation, to form a single beam, the system typically fires:

In convex array operation, to form a single beam, the system typically fires:

• A. All crystals are fired
• B. None are fired
• C. Crystals are fired in alternating groups
• D. Some but not all crystals are fired

Answer: (D)

In forming a single beam with a convex array, the transmitter uses a controlled aperture: only a portion of the crystals are energized, and they are timed (phased) so their waves add up coherently in the desired direction. This selective firing creates a well-defined main lobe while shaping the beam and keeping side lobes under control. If all crystals were fired, you’d lose that deliberate control of the aperture and beam characteristics, and other patterns (like multiple lobes) could arise. Leaving no crystals fired or firing alternating groups would also prevent forming a single, focused beam. So, energizing some but not all crystals achieves the needed single, steerable beam.

In forming a single beam with a convex array, the transmitter uses a controlled aperture: only a portion of the crystals are energized, and they are timed (phased) so their waves add up coherently in the desired direction. This selective firing creates a well-defined main lobe while shaping the beam and keeping side lobes under control. If all crystals were fired, you’d lose that deliberate control of the aperture and beam characteristics, and other patterns (like multiple lobes) could arise. Leaving no crystals fired or firing alternating groups would also prevent forming a single, focused beam. So, energizing some but not all crystals achieves the needed single, steerable beam.