FOCUS - Fonctionnement des multiéléments

Ultrasounds have been widely used to detect acoustic impedance variation in media.  The analysis of the reflected waves on immersed body have be used to detect submarines in water, babies in their mother’s body or cracks in a steel structure which is the purpose of Non destructive Testing (NDT).

Modern phased array techniques considerably enhance the detection capabilities as well as the visualisation of the inside of a structure. For example, phased array techniques are widely used in the medical field to visualise cut view or even 3D full reconstruction of a baby’s body.

Phased array allows steering electronically the ultrasonic beam generated by a probe and then can carry out fast scanning of a structure. The basics of this beam steering by applying a delay law between the elements of a phased array is briefly explain with the game bellow.

The animation bellow shows the beam generated by a probe steered by the application of delay laws (in red) on the element of the probe. This simulation has been carried out using the CIVA sofwtare developped by the French Atomic Energy Commission (CEA).