高功率毫米波返波管器件研究

【作者】 陈洪斌；

【导师】 周传明；

【作者基本信息】 中国工程物理研究院 ， 核技术及应用， 2005， 博士

【摘要】 返波管是输出功率最高的微波器件之一,也是基于超辐射机理的毫米波微波器件中功率和功率转换效率最高的器件。 本论文分为三个部分,第一部分（第二章）研究的是相对论返波管的非线性理论,第二部分（第三章,第四章）是研究普通受激辐射毫米波返波管,第三部分（第4章）是对两种基于超辐射机理的毫米波返波管进行粒子模拟。 本文在一系列假设条件下,给出相互作用区的电磁场表达式。在考虑反向波和同步波都与电子束相互作用条件下,利用Maxwell方程组推导出了相对论返波管的自洽非线性工作方程组。在MATLAB软件平台上编制了计算程序,计算出反向波包络随归一化长度之间的关系曲线,验证了方程组的正确性。 对普通受激辐射毫米波返波管进行粒子模拟和优化设计,在电子束参数:电压170kV、电流800A、脉冲宽度4ns情况下,得到毫米波输出功率25MW、脉冲宽度3ns、效率21%和输出模式为TM₀₁。并给出了归一化输出功率与电子束半径和引导磁场的关系曲线。在第四章对上述模拟结果进行了实验验证,获得了如下的实验结果:在阴极外半径为2.25mm、阴阳极之间的距离为3.5mm、二极管电压～175kV,电流～785A情况下,获得最大辐射功率～18MW、脉冲宽度～3ns、输出模式为TE₁₁单一辐射模式,功率效率～12.9%,在重复频率10Hz情况下进行了运行。粒子模拟结果与实验结果基本一致,得到较好的实验结果,标志国内首次研制成功高功率窄脉冲重复频率的毫米波源。 最后部分对基于超辐射机理的返波管进行了粒子模拟。对基于超辐射机理的毫米波返波管（D/λ=1）进行了粒子模拟,得到优化设计结果:电子束参数～200kV、电流～800A、脉冲底宽～1.2ns、上升前沿和下降沿都～0.1ns和引导磁场强度～3.7T,模拟得到输出功率～75MW、脉冲宽度～350ps、频率～36.5GHz、输出模式为TM₀₁模和功率效率～47%。并给出了归一化输出功率与引导磁场、电子束半径、电子束厚度、电子束脉冲宽度、二极管电压上升前沿、电子束电流和电子束电压之间的关系曲线。首次提出了带反射网的基于超辐射机理的毫米波返波管器件（D/λ=2.65）,并进行了粒子模拟和优化设计。在电子束参数:电压幅值～240kV、电流～3kA、脉冲宽度～1.3ns、脉冲前更多还原

【Abstract】 Backward-wave Oscillator （BWO） is one of the highest power microwave devices, is also the highest power and the highest efficiency millimeter wave microwave devices based on superradiance mechanism.The dissertation mainly involves three parts. In the part 1, consisting of chap.2, the nonlinear theory of relativistic backward wave oscillator （RBWO） is developed. In the part 2, consisting of chap.3 and chap.4, the normal stimulated radiation millimeter wave BWO is investigated. In the part 3, consisting of chap.5, the two millimeter backward wave oscillators based on superradiance mechanism are simulated.In the dissertation, the electric field and magnetic field in the area interacting between the electron beam and the electromagnetic field under a series of hypothesis is listed, the self-consistent nonlinear formulas of the RBWO are derived, the simulation procedure is edited on the MATLAB 6.1 and the curve of the slowly varying magnitude of the backward-wave versus the normalized length is calculated to test and verify the nonlinear formula of the BWO.In the part 2, using the 2.5D, relativistic, fully electromagnetic, PIC code KARAT, the millimeter wave BWO based on normal stimulated radiation is simulated, the results of the optimum design is followings: Employing an annular electron beam with pulse voltage 170kV, current 800A, pulse width 4ns, the millimeter wave output with output power ²5MW, frequency ³9GHz, pulse width ³ns, efficiency ²1% and mode TM₀₁ is obtained. The normalized output power versus the radius of the electron beam and guiding magnetic field are presented. The experiment is carried out to verify the simulation results, the experiment results is followings: Utilizing an annular electron beam with voltage ¹75kV, current ⁷85A, the outer radius of the cathode 2.25mm, the distance between the cathode and the anode 3.5mm, the millimeter wave with power ¹8MW, pulse width ³ns, efficiency ¹2.9% and radiation mode TE₁₁ is obtained, the experiment under the repetition rate 10Hz is also done. There is a good agreement between the numerical simulations and the experiment measurements.In the last part, the optimum designs of two millimeter wave BWO based on superradience mechanism are listed. The optimum design results of BWO （D/λ = 1） isfollowings, exploiting the electron beam with voltage ²00kV, current ⁸00A, pulseduration 1.2ns, the rising time ⁰.1ns, the trailing time —0.1ns, the guiding magnetic filed ³.7T, the millimeter wave with power ^<sup>75MW, pulse width ^<sup>35Ops, frequency ^<sup> 36.5GHz, power efficiency ⁴7% and the radiation mode TMoi is reached., The normalized output power versus guiding magnetic field, the radius of the electron beam, the thickness of the electron beam, the pulse width of the current, the rise time of the diode voltage, the current and the voltage are listed. The over-mode millimeter wave BWO （&/. = 2.65） with/ Areflection net based on superradiance mechanism is presented, simulated and designed, the designed results is following, exploiting the electron beam with voltage ^<sup>240kV, current ^<sup> 3kA, pulse duration 1.3ns, the rising time ⁰.25ns, the trailing time ⁰.2ns, the guiding magnetic filed ⁴.7T, the millimeter wave with power ⁷50MW, pulse width ²00ps, frequency —36.5GHz and power efficiency 104.2% is reached.. The working character of the BWO is developed, the normalized output power versus the rise time of the diode voltage is explain briefly.更多还原