We propose to replace the Gunn Diode Oscillators (GDOs) in NASA?s millimeter- and submillimeter-wave sensing instruments. Our new solution will rely on modern and reliable microwave integrated circuit technology. Specifically our systems will use highly developed microwave oscillators to achieve a low noise and highly stable reference signal in the 10 ? 30 GHz band. Compact amplifiers based on commercial MMIC chips will then increase the signal strength. Finally, our innovative integrated varactor multiplier circuits will be used to increase the frequency to the 60 ? 150 GHz frequency band with high efficiency and minimal added phase noise. With this technology we expect to achieve phase noise and stability comparable to the best Gunn diode oscillators and fundamentally improved output power and frequency agility. The millimeter-wave integrated circuit process and diode technologies are the critical innovative technologies that are required for this research. Through this SBIR project these innovative technologies will be extended to achieve highly compact multipliers for the 60 ? 150 GHz band. These new multipliers will be integrated with highly developed microwave components to achieve a robust and cost efficient replacement for the GDOs presently used in NASA?s Earth Science program.