Harmonic and higher order mode mm-wave klystrons

谐波和高阶模毫米波速调管

• 批准号: ST/K002961/1
• 负责人: Adrian Cross
• 金额: $ 9.13万
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FK002961%2F1
• 关键词: Harmonic; higher; order; mode; mm

The Klystron is a well-known, high efficiency amplifier, with a simple structure and scalable dimensions. It is typically designed with cylindrical reentrant cavities in the fundamental mode. However as the frequency of the device increases the size of the structure decreases. At mm-wave frequencies this leads to two problems: 1) Manufacturing the complex small scale structures. 2) The gap voltage decreases as the gap gets shorter leading to less gain.Most mm-wave klystron concepts reported in the literature are simply smaller versions of microwave klystrons. Even if, in principle the dimensions can be scaled according to the frequency increase, the fabrication challenges and the beam characteristic represent a huge obstacle to the realization of a working device when the frequency is higher than 50 GHz. This is consequently true for the frequency range around 95 GHz, which is of great interest for high bandwidth communication, radar and imaging applications.This proposal is aimed to overcome of the above-mentioned obstacle by the realization of a 95 GHz klystron by two innovative design solutions. The first solution is to operate the cavity at a higher order mode, chosen with similar Ez field distribution in the gap cross-section as the fundamental mode. The design will adopt reentrant cavities with square or rectangular shape, to be compatible with a photolithographic fabrication technique. The higher mode operation permits the design of the cavities with dimensions larger (at least 3-5 times) than in the case of fundamental mode operation. This eases the technological effort and makes possible a high quality fabrication by mechanical micromachining or by photolithographic processes. Further, the beam tunnel can be larger than in fundamental mode, to support higher beam current. In order to increase the interaction a number of intermediate buncher cavities, spaced all along the drift tube, will be used to increase the beam current modulation.A separate approach uses a lower frequency input cavity to modulate the beam current. As the beam travels down the drift tube beam harmonics start to form hence a higher order mode output cavity at an integer harmonic frequency of the input cavity can be excited hence acting as a high power frequency multiplier. As the input can be readily available from a lower frequency and hence more cost effective high power microwave source we are able to overcome any moderate gain of the device.

速调管是一种众所周知的高效率放大器，具有简单的结构和可扩展的尺寸。它通常设计有基模圆柱形凹腔。然而，随着装置的频率增加，结构的尺寸减小。在毫米波频率下，这导致两个问题：1）制造复杂的小规模结构。2)随着差距变短，间隙差距电压减小，导致增益减小。文献中报道的大多数毫米波速调管概念只是微波速调管的较小版本。即使原则上可以根据频率增加来缩放尺寸，但是当频率高于50 GHz时，制造挑战和波束特性代表了实现工作设备的巨大障碍。因此，对于高带宽通信、雷达和成像应用非常感兴趣的95 GHz左右的频率范围，这是真实的。第一种解决方案是在较高阶模式下操作腔，所述较高阶模式被选择为在差距横截面中具有与基模相似的Ez场分布。该设计将采用方形或矩形形状的凹腔，以与可编程制造技术兼容。较高模式操作允许设计尺寸比基模操作情况下大（至少3 - 5倍）的腔。这简化了技术工作，并且使得通过机械微加工或通过光刻工艺的高质量制造成为可能。此外，射束隧道可以大于基模中的射束隧道，以支持更高的射束电流。为了增加相互作用，在漂移管上沿着分布若干中间聚束腔，以增加束流调制，另一种方法是使用低频输入腔来调制束流。随着射束向下行进，漂移管射束谐波开始形成，因此可以激励处于输入腔的整数谐波频率的高阶模式输出腔，因此充当高功率频率倍增器。由于输入可以很容易地从较低的频率获得，因此更具成本效益的高功率微波源，我们能够克服任何中等增益的设备。

项目成果

Investigation of Frequency-Selective Surfaces for a THz Gyromultiplier Output System

太赫兹陀螺倍增器输出系统的频率选择表面的研究

• DOI: 10.1109/ted.2017.2746718
• 发表时间: 2017-11
• 期刊: IEEE Transactions on Electron Devices
• 影响因子: 3.1
• 作者: Xiang Li;Xiaoming LIU
• 通讯作者: Xiaoming LIU

MM-wave cylindrical, periodic-surface-lattice cavities for Cherenkov sources

用于切伦科夫源的毫米波圆柱、周期表面晶格腔

• DOI: 10.1109/irmmw-thz.2013.6665636
• 发表时间: 2013
• 作者: MacLachlan A

Simulation of a G-band sheet beam backward wave oscillator with double staggered metallic rod array

• DOI: 10.1088/0022-3727/46/34/345102
• 发表时间: 2013-08
• 期刊: Journal of Physics D: Applied Physics
• 作者: Guo Liu;Wenlong He;A. Cross;H. Yin;D. Bowes

A Millimeter-Wave Klystron Upconverter With a Higher Order Mode Output Cavity

• DOI: 10.1109/ted.2017.2724581
• 发表时间: 2017-09
• 期刊: IEEE Transactions on Electron Devices
• 影响因子: 3.1
• 作者: G. Burt;Liang Zhang;D. Constable;H. Yin;C. Lingwood;Wenlong He;C. Paoloni;A. Cross

Energetic Charged Particles Above Thunderclouds

雷云上方的高能带电粒子

• DOI: 10.1007/s10712-012-9205-z
• 发表时间: 2012
• 期刊: Surveys in Geophysics
• 影响因子: 4.6
• 作者: Füllekrug M