Single balanced frequency downconverter for direct broadcast satellite transmissions and hybrid ring signal combiner

A circuit for use in a frequency downconverter comprising:

• a passive hybrid coupler comprising first and second input leads each for receiving a different one of a microwave signal and a further frequency signal, and first and second output leads for outputting, respectively, first and second combined signals with each of the first and second combined signals comprising a combination of the microwave and further frequency signals but with at least one of the microwave and further frequency signals of one of the microwave and further signals being out of phase with the same at least one microwave and further frequency signal of the other of the first and second combined signals, said coupler comprising a convex shaped portion and a concave shaped portion, the first and second input leads connected, respectively, to the convex portion and the concave portion, said second input lead passing over the convex portion, and the first and second output leads connected to the concave portion on an outer periphery of the coupler, the first and second input and output leads each being connected at spaced apart positions to and along the coupler so that the first and second combined signals are formed at the first and second output leads, respectively;
• and
• a monolithic microwave integrated circuit semiconductor chip comprising,
• a first input port for receiving the first combined signal, a second input port for receiving the second combined signal, and an output port,
• a single balanced mixer comprising a first single ended mixer for converting the first combined signal to a first intermediate frequency signal, and a second single ended mixer for converting the second combined signal to a second intermediate frequency signal, and
• an amplifier for forming an amplified unbalanced intermediate frequency signal at the output port representative of said first and second intermediate frequency signals.