电子注通道形貌对折叠波导慢波结构的影响  

Impact of the electron beam tunnel on a folded waveguide slow-wave structure

作　　者：王亚军[1,2] 陈樟[1,2] 施志贵[1] 

机构地区：[1]中国工程物理研究院电子工程研究所,四川绵阳621900 [2]中国工程物理研究院太赫兹研究中心,四川绵阳621900

出　　处：《激光与红外》2013年第6期678-682,共5页Laser & Infrared

摘　　要：折叠波导结构是一种极具潜力的太赫兹行波管慢波电路。分析了电子注通道形貌对折叠波导高频特性的影响,包括色散特性、耦合阻抗和衰减特性。仿真结果表明,相比于圆形电子注通道,矩形电子注通道的折叠波导结构色散要略微陡一些,损耗也要略微高一些。在中心频率处,矩形电子注通道结构的耦合阻抗比圆形电子注通道结构低0.5Ω左右。皮尔斯小信号理论表明,在中心频率处,矩形电子注通道结构和圆形电子注通道结构的增益速率分别为4.85 dB/cm和5.22 dB/cm,具有相似的3 dB带宽,约为6.3 GHz和7.2 GHz。粒子模拟表明,对于矩形和圆形电子注通道,54 mm(100个周期)的折叠波导慢波结构在220 GHz增益分别为24.42 dB和28.44 dB。The folded waveguide structure is a promising slow-wave structure for terahertz traveling wave tubes. The influence of the beam tunnel on the circuit cold characteristics was analyzed, including dispersion relation, interaction impedance and circuit attenuation. The simulation results show that a beam tunnel with a rectangular cross section exhibits slightly steeper dispersion relation and higher attenuation coefficient than the beam tunnel with a circular cross section. Compared with the beam tunnel with a circular cross section, interaction impedance of beam tunnel with a rectangular cross section is lower about 0. 5 Ω at a 220 GHz central frequency. For cold beam, the linear theory predicts a gain growth rate of 4.85 dB/cm and 5.22 dB/cm, respectively. They have a similar 3dB bandwidth of 6.3 GHz and 7.2 GHz. The large signal simulations show that the nonlinear gain is 24.42 dB and 28.44 dB at 220 GHz for 54 mm （100 periods）folded waveguide slow-wave structure with rectangular cross section and circular cross section, respectively.

关 键 词：冷测特性 折叠波导 慢波结构 太赫兹辐射 行波管 

分 类 号：O441[理学—电磁学]