Which term is used to describe unwanted beams produced by a multielement transducer that propagate away from the main beam?

Which term is used to describe unwanted beams produced by a multielement transducer that propagate away from the main beam?

• A. Grating lobes
• B. Side lobes
• C. Backlobes
• D. Noise lobes

Answer: (A)

Grating lobes describe unwanted beams from a multielement transducer that travel away from the main beam. They arise when the element spacing is large relative to the wavelength, causing additional directions where the element fields interfere constructively to create secondary maxima in the radiation pattern. These off-axis beams can degrade image quality by producing artifacts or false signals. Keeping spacing at or below half a wavelength and using apodization helps suppress these lobes.

Grating lobes describe unwanted beams from a multielement transducer that travel away from the main beam. They arise when the element spacing is large relative to the wavelength, causing additional directions where the element fields interfere constructively to create secondary maxima in the radiation pattern. These off-axis beams can degrade image quality by producing artifacts or false signals. Keeping spacing at or below half a wavelength and using apodization helps suppress these lobes.