High power submillimeter-wave varactor frequency multipliers based on quasi-vertical Schottky diodes.
Submillimeter-wave technology has received substantial attention in the past decades, for its use in a variety of important applications, including radio astronomy, spectroscopy, plasma diagnostics, radar, imaging, and potentially communications. One of the factors that limit the widespread of this technology is the lack of high power solid state sources, often coined the “terahertz gap”. Frequency multipliers are the best candidates to provide a source of stable, reliable, and compact power at terahertz. However, their efficiencies significantly degrade after each multiplication stage, leading to very low powers at 1 THz. One way of addressing this issue is to increase the input power to the first multiplication stage. Thus, power handling has become a major concern. This project proposes a transformative approach to improve the thermal management and output power of frequency multipliers, by investigating new device geometries, fabrication processes, design innovations, and electrical and thermal characterization techniques. The end goal is to prototype and characterize a 520 GHz multiplier chain, with 10 mW of output power.