lnb

lnb is an acronym that can refer to more than one concept, but in technical contexts it most commonly denotes the low-noise block downconverter. An LNB is a compact front-end receiver mounted on the feed of a satellite dish. Its primary role is to receive microwave signals collected by the dish, amplify them with a low-noise amplifier, and convert them to a lower frequency for transmission over a coaxial cable to the satellite receiver.

Typically, an LNB uses a mixer with a local oscillator to shift the high-frequency signal down to an intermediate frequency (IF) in the range of about 950 to 2150 MHz. The LO frequency is chosen to set this IF band and is stabilized for consistent performance. Most modern LNBs operate in the Ku-band (about 10.7–12.75 GHz input) or C-band ranges, with appropriate band-specific designs. Common variants include universal LNBs that cover wide RF ranges and allow LO switching, as well as dual- or quad-output models for multiple receivers, and polarization-capable designs for linear or circular polarization.

While LNB is most often written in uppercase as LNB, lowercase lnb is simply a typographic variant. In contexts outside satellite reception, “lnb” has no single widely adopted definition.