What is the total number of elements used by the focal law if a 64-element probe has an active aperture of 0.39 in. and element pitch of 0.01 in.?

To determine the total number of elements used by the focal law with a 64-element probe, an understanding of active aperture and element pitch is essential. The active aperture is the width that can be used effectively for scanning, while the element pitch is the distance between the centers of two adjacent elements.

In this scenario, the active aperture is given as 0.39 inches, and the element pitch is 0.01 inches. To find the number of elements that fit within the active aperture, we can divide the width of the active aperture by the element pitch:

Number of elements = Active aperture / Element pitch

Using the provided values:

Number of elements = 0.39 inch / 0.01 inch = 39 elements

However, this calculation indicates that there are potentially 39 elements that can be utilized in the active aperture. If we need whole elements, the feasible approach would be to round down or determine how many full elements can actually be used given that the probe consists of only 64 elements.

Consider the options offered: while we derived a figure of 39 from the direct calculation, in practice, many focal laws for phased array approaches have a standard operating number that often rationalizes down to a lower value to ensure consistent beam