0.22THz折叠波导返波管理论和实验研究

发布时间：2018-01-14 13:48

  本文关键词：0.22THz折叠波导返波管理论和实验研究　出处：《清华大学》2015年博士论文　论文类型：学位论文

  更多相关文章： 太赫兹 返波管 折叠波导 一维模型 误差分析 起振电流

【摘要】：太赫兹返波管(THz-BWO)是认知、研究并利用太赫兹波的一个有力工具。随着大电流阴极的发展和微细加工技术的普及,采用折叠波导(FW)慢波结构和圆柱状电子束的THz-BWO开始成为一种可行的技术方案。论文针对0.22 THz折叠波导返波管(FW-BWO)进行了理论分析,数值模拟和实验研究。提出了用于FW-BWO束波互作用分析的一维(1-D)理论,研究了束流光学系统发射热初速的问题,发展了非常规盒型窗的等效电路模型,并进行了高频样管的实验研究。首先,论文建立并验证了有损折叠波导慢波结构的等效电路模型。同时在考虑太赫兹高频损耗,相对论效应,端部反射,空间电荷效应的情况下,建立了描述FW-BWO中束波互作用的小信号,大信号频域理论模型及时域1-D理论模型。在此基础上,进一步发展了理论模型,使其可以考察非理想电子注和慢波不规则的影响,可以用于进行快速的误差分析。其次,在考虑相对论效应的情况下建立了基于收敛性皮尔斯电子枪和傍轴电子束包络轨迹方程,并讨论了傍轴电子束在布里渊磁场下的聚束规律。然而,更进一步研究发现横向热初速会显著改变低导流系数电子枪电子注的运行包络。因此提出了将基于微扰法的经典理论模型和考虑热初速的数值模型相互对比,迭代修正的综合设计方法。然后,论文讨论了THz-BWO输能结构的理论模型:提出了采用蓝宝石窗片的非常规盒型窗结构,并发展了研究该结构的等效电路模型,讨论了其中的谐振模式;对匹配负载中的衰减瓷电参数测试提出了一种简化的传输反射法;利用耦合波理论和场匹配理论发展了过渡段散射参数的计算方法。之后完成了对0.22 THz折叠波导返波管的整管理论、工程设计和高频误差分析,并探索了关键步骤的工艺方案。在束流光学系统和输能系统的成功研制基础上,加工测试了两套不同高频方案的高频样管,并开展了实验研究。虽然理想模型指出返波管可能达到百毫瓦至瓦级的功率输出,但主要由于慢波变形导致相速度零散以及电子注非理想的原因,两套高频样管的起振电流相对工作电流都有不同程度的提高。最终,首次完成了0.22 THz折叠波导返波管的原理验证实验,最高可以在17.47 kV下获得12.22 mA的收集极电流,此时流通率为77%,重复频率100 Hz,占空比为1/10,PM4测定峰值功率最高为36 mW,频率约为0.229 THz。
[Abstract]:Terahertz backward wave oscillator (THz-BWO) is a cognitive research, and the use of a powerful tool for terahertz wave. With the development of high current cathode and microfabrication technology, using folded waveguide slow wave structure (FW) and cylindrical electron beam THz-BWO has become a feasible technical scheme aiming at 0.22 THz. Folded waveguide BWO (FW-BWO) by theoretical analysis, numerical simulation and experimental research. For one-dimensional analysis of FW-BWO beam wave interaction is proposed (1-D) theory, studies the beam thermal velocity of optical system development flow, the equivalent circuit model of unconventional box type window, and carried out experimental studies high frequency of the sample tube. Firstly, this paper establishes the lossy folded waveguide slow wave structure equivalent circuit model. At the same time considering the terahertz frequency loss, relativistic effect, end reflection, space charge effect, the establishment of the tracing Small signal in the FW-BWO beam wave interaction, frequency domain and time domain model theory 1-D theory model. On this basis, the further development of the theoretical model, which can influence the non ideal electron beam and slow wave and irregular, can be used for fast error analysis. Second, in considering the effect of relativity the case is established based on the convergence of the Pearce electron gun and paraxial electron beam envelope equation, and discusses the paraxial electron beam bunching in the Brillouin magnetic field law. However, further study found that the operational envelope of transverse thermal initial velocity will significantly change the low perveance electron gun electron beam. So the classic the theoretical model of perturbation method and numerical model considering mutual thermal initial velocity based on the integrated design method of modified iteration. Then, this paper discusses the theoretical model of THz-BWO power transmission structure was proposed by blue Unconventional box type window structure of gem window, and the equivalent circuit of the structure of the model, discussed the resonant mode; the matching attenuator electric parameter test of proposed transmission and reflection method of a simplified load calculation method; by using the coupled wave theory and field theory, the development of the scattering parameters the transition section. After completion of the 0.22 THz folded waveguide BWO tube theory, engineering design and analysis of high frequency error, and explores the key steps in the process. The beam optical system and transmission system can be successfully developed on the basis of test sample processing high frequency two different sets of high frequency scheme tube. Experimental researches are carried out. Although the ideal model indicates that the BWO may reach 100 MW power output to the watt level, but mainly due to the slow wave phase velocity and deformation due to scattered electron beam non ideal, two sets of high frequency tube The relative work starting current current are improved to different degrees. Finally, the completion of the first 0.22 THz folded waveguide BWO principle experiment, can get a maximum of 12.22 mA at 17.47 kV of the collector current, the flow rate was 77%, the repetition rate is 100 Hz, the duty ratio is 1/10, PM4 determination the highest peak power is 36 mW, the frequency is about 0.229 THz.

【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN125
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本文编号：1423870