Attenuator

In telecommunication, the term attenuator has the following meanings:

• In electrical systems, a network that reduces the amplitude of a signal without appreciably distorting its waveform. Electrical attenuators are usually passive devices. The degree of attenuation may be fixed, continuously adjustable, or incrementally adjustable. Fixed attenuators are often called pads, especially in telephony. The input and output impedances of an attenuator are usually matched to the impedances of the signal source and load, respectively.

• In optical systems, a device that reduces the amplitude of a signal without appreciably distorting its waveform. Optical attenuators are usually passive devices. The degree of attenuation may be fixed, continuously adjustable, or incrementally adjustable.