A LNB (acronym which stands for Low Noise Block Downconverter) is a device composed of a feed horn, a polarizer and a converter.
Placed in the receiving satellite dish focus, it is employed to convert the satellite signals transmitted in KU band (typically from 10700 MHz to 12750 MHz) in a lower frequency band (950-2150 MHz), the so-called 1 IF (First Intermediate Frequency) , thus allowing the distribution of satellite signals to the decoders using a coaxial cable.