English: Low-noise block downconverter (LNB) from a satellite television dish, disassmbled. This is mounted at the focus of the satellite dish and converts the microwave k_u band signal from the satellite to a lower intermediate frequency which is sent down the coaxial cable into the house to the set-top box at the user's TV. A feed horn collects the microwaves from the dish into a circular waveguide which passes through the hole in the circuit board. The two metal pins visible at the edge of the hole act as antennas to receive the two orthogonal circularly polarized microwave signals. On the circuit board a local oscillator creates a signal which is mixed with the microwave signal, creating the intermediate frequencies, which are output to the coaxial cable through the connectors at bottom.