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.

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.

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.

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.

Apodization is a method for reducing side lobes (lateral array elements) in some arrays. It gradually decreases the vibration of the transducer surface with distance from its center by improving the directivity. It is usually accomplished by using more power to excite the innermost elements.