STTR Phase I: Metamaterial Based Vacuum Electron Devices for Next Generation Communication Systems

该小企业技术转让（STTR）第一阶段项目旨在开发真空电子器件（VED）的新技术，如行波管（TWT），用于下一代高频谱效率，高数据速率民用和军用通信系统。VED放大器采用频率选择性互作用结构（IS），在工作频带内具有高增益，而在相邻频带内具有可忽略的杂散输出，从而获得高频谱效率，可以大大提高VED放大器的性能。本计画旨在研制一种新型的超材料结构行波管。MTM可以被设计为同时具有大的负的介电常数（ε）和磁导率（ε），这导致电磁波的左手传播与电子束的高耦合。而且，这种结构允许电子束在IS的介质中共同传播，允许选择空间分布的高电流电子束以实现更高的增益和输出功率。作为拟议的研究的结果，一个10 GHz的行波管的MTM IS将被设计，测试和表征。将开发一种概念验证行波管设计，该设计将有可能推动高数据速率通信系统的最新技术水平。该项目的更广泛影响/商业潜力包括在波导、滤波器、混频器、功率合成器和信道分出滤波器等无源元件的新型设计方面取得进展。这些组件的性能的进步对于提高下一代通信系统的系统级性能至关重要。在这项工作下开发的设计方法也将适用于其他微波和太赫兹源，如VED为基础的回旋管和半导体为基础的太赫兹源，如量子级联激光器（QCL），通过使用MTM结构，以改善所需模式的限制和过滤不需要的模式。此外，MTM的进一步发展将为光的操纵和传输创造新的技术，这是光学计算的基本组成部分。使用MTM解决有源和无源微波和太赫兹器件中的问题的概念的发展将有助于理解MTM的基本物理和推进微波工程领域。

This Small Business Technology Transfer (STTR) Phase I project aims to develop novel technology for Vacuum Electron Devices (VED) such as Traveling Wave Tubes (TWT) for the next generation high spectral efficiency, high data rate civilian and military communication systems. VED amplifier performance be greatly improved by employing frequency selective interaction structures (IS) with high gain in the operating band and negligible spurious output in the neighboring bands for achieving high spectral efficiency. This project aims to develop a novel TWT with a metamaterial (MTM) IS. MTMs can be engineered to simultaneously have large negative values of permittivity (å) and permeability (ì) which cause left handed propagation of electromagnetic waves with high coupling to the electron beam. Also, such structures allow co-propagation of an electron beam in the medium of the IS, permitting the choice of a spatially distributed high current electron beam to achieve higher gain and output power. As a result of the proposed research an MTM IS for a 10 GHz TWT will be designed, tested and characterized. A proof-of-concept TWT design will be developed which will have potential to advance the state-of-the-art in high data rate communication systems.The broader impact/commercial potential of this project includes advances in novel designs of passive components such as waveguides, filters, duplexers, power combiners and channel drop filters. Advances in the performance of these components are crucial to advancing system-level performance of the next generation communication systems. The design methodology developed under this work will also be applicable to other microwave and terahertz sources such as VED based gyrotrons and semiconductor based Terahertz sources such as Quantum Cascade Lasers (QCL) by using an MTM structure to improve confinement of desired modes and filtering the unwanted modes. Also, further development of MTMs will create new technology for the manipulation and transportation of light which is the basic building block for optical computing. The development of the concept of using MTMs for solving problems in both active and passive microwave and terahertz devices will contribute to the understanding of the basic physics of MTMs and advance the field of microwave engineering.