Slow Wave Structure Analysis for a Thz Solid State Traveling Wave Amplifier

On the electronic (RF) side of the THz gap, both solid-state transistors and vacuum electronic devices struggle to reach 1mW at 1THz largely due to the diminishing wavelength. Transistors scaled for THz operation have gate lengths << 100nm and cannot support sufficient width to produce appreciable power at this frequency. Vacuum beam traveling wave amplifiers are electrically large, but still struggle with fabrication and magnetic field tolerances at the required circuit dimensions. We combine the best attributes from both these fields of research into a solid-state traveling wave amplifier. We have derived an extension to the classical Pierce theory [1] to couple high density 2DEG plasma waves present at certain semiconductor heterostructure interfaces to a generic slow wave circuit. In this work, we present possible slow wave structures based on planar semiconductor fabrication techniques. EM simulations are shown, including losses in the THz regime, and the resulting gain from a numerical Pierce-style calculation. A brief discussion about the challenges of a full ‘hot tube’ style simulation is also included.