Traveling wave amplification from multi-beam slow wave structures for high power millimeter and THz wave generation

Summary form only given. In an effort to develop compact millimeter and THz wave radiation power sources, two types of traveling wave amplification concept with multi-beam have been studied using Pierce small signal analysis and particle-in-cell (PIC) simulation. Our prior work includes theoretical and numerical assessment on performance of the aluminum-nitride (AlN)-loaded multi-beam structure, indicating that the TM₃₁-mode is amplified with 26-30 dB/beam at 64-84 GHz with three elliptical beams, simultaneously suppressing lower order modes (TM₁₁, and TM₂₁). The same analysis also shows that multi-staged cascading enables > 50 W of radiation power with 30 dB gain, which could be integrated on a single board substrate with multi-beam emitters by micro-fabrication. More schemes to improve device performance and to reduce physical sizes are continuously explored in advancing millimeter and sub-millimeter power radiation sources.