Octave Input, S-TO K/sub a/-Band Large-Signal Upper-Sideband Varactor Upconverter

The S-to K/sub a/-band varactor upconverter described herein provides significantly greater power output/bandwidth capability than obtainable from a single-sideband resistive modulator, leading to significant potential simplification in high-modulation-rate millimeter wave transmitters. This upconverter uses high quality varactors and a unique design to provide octave (2-4 GHz) instantaneous input bandwidth, and a flat (6-9 mW), 2 GHz-wide K/sub a/-band output power-frequency response with minimum K/sub a/-band pump power expenditure.