Down Converters are parts of a microwave link. Microwave signals like DVB-T with COFDM modulation are for example generated from a wireless video transmitter in different frequency bands. Common video receiver input frequency range goes up to about 1 GHz. All frequency bands above 1 GHz like L-Band, S-Band or C-Band can be converted in the receiver input frequency with a frequency converter. These frequency converters are named down converter, LNC (low noise converter) or LNB (low noise block). The down converter normally is a combination of low noise amplifier, RF filter, RF mixer and a local oscillator to generate the mixing frequency. Water resistant down converters can be installed directly at the antenna. The down converted signal (IF signal) of the converter can transferred with a coaxial cable to the receiver. In most applications the supply voltage for the down converter comes from the receiver (remote power supply).Microwave links can be found in very different applications. A main part is the transmission of video and audio signals from events, sport events or surveillance applications.
