Why Trust Techopedia

What Does Attenuation Mean?

Attenuation is a telecommunications term that refers to a reduction in signal strength commonly occurring while transmitting analog or digital signals over long distances.


Attenuation is historically measured in dB but it can also be measured in terms of voltage.

Techopedia Explains Attenuation

Attenuation can relate to both hard-wired connections and to wireless transmissions.

There are many instances of attenuation in telecommunications and digital network circuitry.
Inherent attenuation can be caused by a number of signaling issues including:

  • Transmission medium – All electrical signals transmitted down electrical conductors cause an electromagnetic field around the transmission. This field causes energy loss down the cable and gets worse depending upon the frequency and length of the cable run. Losses due to
  • Crosstalk from adjacent cabling causes attenuation in copper or other conductive metal cabling.
  • Conductors and connectors – Attenuation can occur as a signal passes across different conductive mediums and mated connector surfaces.

Repeaters are used in attenuating circuits to boost the signal through amplification (the opposite of attenuation). When using copper conductors, the higher the frequency signal, the more attenuation is caused along a cable length. Modern communications use high frequencies so other mediums which have a flat attenuation across all frequencies, such as fiber optics are used instead of traditional copper circuits.

Different types of attenuation include:

  • Deliberate attenuation can occur for example where a volume control is used to lower the sound level on consumer electronics.
  • Automatic attenuation is a common feature of televisions and other audio equipment to prevent sound distortion by automatic level sensing that triggers attenuation circuits.
  • Environmental attenuation relates to signal power loss due to the transmission medium, whether that be wireless, copper wired or fiber optic connected.

Related Terms

Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.