In a convex array each crystal is about _________ in width.

• A. 1 wavelength
• B. Half a wavelength
• C. Two wavelengths
• D. A quarter wavelength

Answer: (A)

In ultrasound transducer design, the width of each crystal is tied directly to the acoustic wavelength in the medium. Making each element about one wavelength wide provides efficient conversion of electrical energy into sound and supports a broad, useful bandwidth, which helps form a well-defined, focused beam for good lateral resolution. If the element were much thinner than a wavelength, energy transfer would be less efficient and the sensitivity would drop, leading to weaker signals. If the element were much wider than a wavelength, grating lobes and poor focusing could arise, degrading beam quality. A width near one wavelength offers a practical balance between efficiency, bandwidth, and beam control, so each crystal in a convex array is about one wavelength in width.