Fundamental Studies of Electronic Properties of Materials and Devices for High Power, Compact Terahertz Vacuum Electron Devices.

摘要

The results of this investigation have yielded two major new research capabilities and several important advances in physical understanding of materials and devices at high (THz-regime) frequencies. A quasi-optical cavity THz measurement system was developed with a record-high Q and resolution capable of measuring differences in surface conductivity less than 10% at frequencies between 300- 1000 GHz. A multi physics computational model (EMC, FDTD, MD) was developed for electron transport in solid conducting media under electromagnetic radiation driving forces. New discoveries were made about the losses of high frequency THz radiation in conducting media, including the effects of moderate conductivity (semi-conductors) and surface roughness. Experiments were also completed that characterized the effect of water vapor on atmospheric attenuation of THz radiation. Those data were in excellent agreement with the Millimeter-Wave Propagation Model, even though that model was originally developed for the lower millimeter-wave frequencies.