Reflex klystrons

Description:

The reflex klystron was used as a microwave source (in GHz range) with variable frequency and a few mW power. It was a key component of the first satellite receivers and microwave radio links (e. g. a line from a TV studio to a transmitter). The output of the klystron would be mixed with the incoming microwave signal, the resulting signal had lower frequency and could be processed with ordinary electronic circuits.