Traveling wave tubes are rapidly evolving to provide unprecedented power level in comparison to solid state devices in the millimeter waves region of the spectrum (80 – 300 GHz) thus enabling a wide range of applications. Wireless communications, imaging, security, plasma diagnostics, healthcare and many others will gain substantial features if high power in the millimeter wave region would be available from compact sources. The development of fabrication technologies is proving crucial for introducing new topologies and structures for millimeter wave vacuum electronic devices, compatible with the dimensions dictated by the short wavelength that poses substantial challenges due to tight tolerances and surface quality. This review paper will provide an overview of the principles, evolution and state of the art of one of the most widely utilized vacuum electronic devices, the traveling wave tube (TWT). The wide band, high gain features of TWTs make those devices the most promising solutions for high power at millimeter waves and THz frequencies.

中文翻译：

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面向 21 世纪的毫米波行波管

与毫米波频谱 (80 – 300 GHz) 频谱范围内的固态设备相比，行波管正在迅速发展，以提供前所未有的功率水平，从而实现广泛的应用。如果毫米波区域的高功率可以从紧凑的源中获得，无线通信、成像、安全、等离子诊断、医疗保健和许多其他领域将获得重要的功能。事实证明，制造技术的发展对于为毫米波真空电子设备引入新的拓扑和结构至关重要，这些拓扑和结构与短波长所规定的尺寸兼容，由于严格的公差和表面质量而带来了巨大的挑战。这篇评论文章将概述这些原则，应用最广泛的真空电子设备之一——行波管 (TWT) 的演变和最新技术。TWT 的宽带、高增益特性使这些设备成为毫米波和太赫兹频率高功率最有前途的解决方案。