What is the effect of a larger planar passive aperture on beam focusing and steering?

A larger planar passive aperture enhances the resolving power of a phased array system by allowing for deeper range focusing and producing a narrower beam length.

When considering beam focusing, a larger aperture provides a more effective means to gather and utilize sound waves, leading to a more focused beam that can penetrate deeper into the material being inspected. This is due to the improved ability to control wavefronts emitted from the array, which enhances the focus at greater depths.

Furthermore, a narrower beam length is a result of the larger aperture because the increased dimensions of the aperture reduce the diffractive spread of the beam. This leads to improved lateral resolution and more precise localization of flaws or discontinuities within the inspected material.

In summary, the correct answer reflects the benefits of a larger planar passive aperture, resulting in a deeper range focusing effect coupled with a narrower beam length, allowing for better detection capabilities in ultrasonic testing scenarios.