Attenuator

An attenuator is a telecommunication device that reduces the amplitude of a signal without appreciably distorting its waveform. Attenuators are usually passive devices, and can either be. The degree of attenuation may be fixed, continuously adjustable, or incrementally adjustable.

Fixed electrical attenuators are often called pads, especially in telephony. The input and output impedances of an electrical attenuator are usually matched to the impedances of the signal source and load, respectively.