Low noise SSB mixer for HF receiver - has single oscillator providing mixing and pump signals for mixing circuit and parametric amplifier

摘要

The low-noise single-sideband mixer, for HF receivers, has a mixing circuit (21) coupled by its IF output to a parametric amplifier (24) and to an IF amplifier (27). The parametric amplifier's output is fed back to the mixing circuit's HF input. The mixing oscillator (22) is connected to both the mixing circuit and the parametric amplifier to provide a mixing signal and a pumping signal respectively. The mixing circuit contains two mixers each connected between a shared HF input and an output coupler. The latter's output carries the IF signals. The oscillator's output is applied to both mixers via a second coupler.