Improved single-sideband microwave upconverter using injection of unwanted sideband

It is demonstrated for the first time that the unwanted sideband output from a single-sideband frequency converter can be substantially reduced by using a novel unwanted sideband injection technique. Tests carried out on a prototype operating at L-band have shown 20 dB improvement of sideband suppression over current state of the art. This is achieved without filtering and therefore the technique is potentially useful for the future development of integrated transmitters in microwave and millimetre-wave applications.