The main lobe is the main acoustic transducer beam. There are other, smaller lobes called side lobes that are located around the main lobe.

See also Side Lobe, Grating-lobe Artifact, Beam Steering, Beamforming.

Beam steering is a method of steering the main lobe of a transducer to a certain direction. Array transducers have the ability to be steered as well as focused. Like focusing, the beam is directed by sequentially stimulation of each element. This feature creates the sector scan by rapidly steering the beam from left to right to give the two dimensional cross sectional image.

The dimension of the ultrasound beam and the transducer array are the origin of grating-lobe artifacts (also called side lobe artifact). Grating lobes as side lobes are off-axis secondary ultrasound beams projecting at predictable angles to the main lobe. Side lobes are too small to produce important artifacts.

See also Apodization, and Subdicing.

Side lobes are secondary and smaller acoustic beams falling outside at predictable angles located around the main lobe.

See also Grating-lobe Artifact, Amplitude Shading, and Apodization.

Amplitude shading is a method of reducing the side lobe levels in a transducer array. The shading usually causes the main beam to broaden by applying different voltages to the elements of the array.

See also Analog Output Signal.