We propose to use photonic band gap (PBG) structures for constructing traveling wave tubes (TWTs) at 100 GHz, a completely novel approach. Using a PBG fiber allows us to create an all-dielectric slow-wave structure with very large band width and low losses in the mm-wave regime, compared to TWTs made out of metals. Additional capabilities such as mode selectivity are also achievable. We designed two 100 GHz pencil beam PBG TWTs using Ansoft's HFSS, 3D electromagnetic simulation software for high frequency applications. The first design is a periodic array of vacuum rods in a dielectric matrix, with a smaller vacuum rod forming the line defect. A fiber drawing procedure is being utilized to construct this design out of fused silica. The second structure is a periodic array of dielectric rods in a vacuum matrix, surrounding a thick hollow dielectric tube that accommodates the electron beam. This model is being fabricated out of silicon by means of high-pressure laser chemical vapor deposition (HP-LCVD), a versatile approach to synthesize fibers from the vapor phase. Additionally, a scaled 10 GHz cold test made from alumina rods is being produced for design confirmation purposes, and a 100 GHz sheet beam PBG TWT is being investigated for even greater power generation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.