Also known as: attenuation

Attenuation is the reduction of signal strength as energy passes through a medium, cable, connector, or obstacle.¹ It is expressed in decibels and subtracts directly from a power budget.

Attenuation is the loss of signal strength as energy spreads out and is absorbed along the path.

How it works

Every metre of coax, every connector, and every wall or tree adds loss — generally more at higher frequencies. Free-space spreading is a specific kind of attenuation called path loss.

Relevance to SDR

Keeping cable runs short and connectors clean minimises attenuation between antenna and receiver, preserving SNR.

Sources

1. Attenuation — Wikipedia, for the general definition and causes of signal loss. ↩

See also

• Path loss
• Decibel (dB)
• Radio propagation
• Antenna

Learn it step by step

• How signals travel