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圆台谐振腔和微波产生及传输装置可以形成一套和外界独立的微波谐振器系统.由于壁面上电磁压强差的作用,圆台谐振腔可能产生净电磁力,这需要从实验上给予证明.为此首先应对独立的微波谐振器系统进行调谐实验研究,使系统时刻处于谐振状态,这是实验证明净电磁力存在的重要保证.为此,本文对圆台谐振腔进行低信号调谐实验,同时配合调谐元件,准确地调试2.45 GHz频率下的谐振状态,分析温度对谐振状态的影响.实验结果表明该微波谐振器谐振频率2.44895 GHz、品质因数117495.0823,而且当腔体壁温升高时谐振频率减小、品质因数出现周期性振荡. 相似文献
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分析了同轴腔体间隙束流与电场的相互作用,推导了同轴腔体间隙的耦合系数和电子负载电导,并设计了104 W级注入微波驱动的X波段三重轴相对论速调管放大器,产生了GW级的微波功率输出.通过三维粒子模拟,设计了工作频率为9.37 GHz的三重轴相对论速调管放大器,在注入微波功率为70 kW、束压为600 kV、束流为5 kA的条件下,获得的输出微波功率达到1.1 GW,效率为37%,增益为42 dB.
关键词:
同轴腔体
束波互作用
X波段
三重轴相对论速调管放大器 相似文献
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设计了工作在X波段的相对论速调管放大器同轴双间隙输出结构,并采用3维PIC程序对其进行了粒子模拟,分析了输出微波功率随直流渡越角、输出腔品质因数值等相关参数的变化,对输出腔体结构进行了优化设计。模拟结果表明:同轴双间隙输出结构可以降低束流的势能,增加束流与腔体的作用时间,提高速调管的微波提取效率。模拟中采用束压600 kV、束流5 kA、调制深度100%和峰值频率9.37 GHz的电子束以及1T的轴向引导磁场强度,得到了周期平均功率1.2 GW、峰值频率9.37 GHz、效率40%的微波输出。 相似文献
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为了计算高品质因数谐振腔的储能过程和泄能过程,将高品质因数谐振腔的输入膜片和输出结构分别建模为一个二端口网络和一个三端口网络,根据高品质因数谐振腔的信号流图,提出了一种基于递推的数值计算方法。用该方法设计了一个工作在2.92 GHz附近的基于BJ32波导的高品质因数谐振腔,给出了谐振腔的储能过程和泄能过程。当输入膜片开口宽度取20 mm、输出膜片开口宽度取60 mm时,计算得出的谐振频率为2.9198 GHz,饱和储能时间为2.6 μs,输出脉冲宽度6.82 ns,输出峰值增益为129.6,能量效率为0.169。 相似文献
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为进一步提高X波段相对论速调管放大器的输出功率,采用理论分析与粒子模拟的方法对双群聚腔级联式相对论速调管放大器进行了研究。分析了提高注入腔对注入微波吸收效率的方法,分析了群聚腔调制能力与腔体模式、Q值等参数的关系,分析了输出腔提取效率与Q值的关系。在三维粒子仿真中,设计了模式反射器抑制TEM模式泄露与杂模振荡,得到了功率超过2.5 GW,频谱纯净,频率锁定为8.40 GHz,输出输入微波相位差稳定,抖动不超过2°的高功率微波输出。 相似文献
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An analytic circuit model for slot coupling from a waveguide to a loop-gap resonator (LGR) in a context of electron paramagnetic
resonance (EPR) spectroscopy is presented. The physical dimensions of the waveguide, iris, LGR, and aqueous sample are transformed
into circuit values of inductance, capacitance, and resistance. These values are used in a solution of circuit equations that
results in a prediction of the radio frequency (rf) currents, magnitude and phase, frequency, and magnetic and electric stored
energies near the critical coupling. The circuit geometry reflects magnetic flux conservation between the iris and LGR as
well as modification of the outer loop LGR currents by the iris. Unlike conventional models, coupling is not explicitly based
on a mutual inductance between the iris and LGR. Instead, the conducting wall high-frequency rf boundary condition is used
to define surface currents, regions, and circuit topology with lumped-circuit values of self-inductance, capacitance, and
resistance. Match is produced by a combination of self-inductive and capacitive circuit coupling. Two conditions must be met
to achieve match. First, the equivalent resistance of the LGR as seen by the iris must be transformed into the waveguide characteristic
impedance. This transformation is met at a particular frequency relative to the natural LGR resonance frequency. The frequency
shift magnitude is largely determined by the LGR properties, weakly dependent on the iris length and placement, and independent
of other iris dimensions. The second condition for match is that the iris reactance at this frequency shift must cancel the
residual reactance of the LGR. This second condition is sensitive to the iris dimensions. If both conditions are not simultaneously
satisfied, overcoupling or undercoupling results. A slotted iris with a length equal to the size of the large dimension of
the waveguide is found to have many properties opposite to a conventional iris with shorter length. Notably, the magnetic
field near the iris tends to reinforce rather than oppose the magnetic field in the resonator. The long iris improves the
LGR EPR performance by providing increased rf magnetic field homogeneity at the sample, higher signal, and reduced total frequency
shift since the shifts due to sample and iris tend to cancel. Investigations reveal that the first match condition can be
adjusted by LGR dimensional changes and such adjustment can eliminate the frequency shift. Results are consistent with Ansoft
High Frequency Structure Simulator (Version 10.1, Ansoft Corporation, Pittsburgh, PA) simulations and can be extended to cavity
resonators. 相似文献
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随着海洋环境武器装备隐身发展的需要, 开展具有微波低通高阻特性的复合材料构件设计与研究显得重要而迫切. 文章首先设计了一种中空六边形周期性结构, 以此为基础设计了一个由面层、中空六边形环周期层1、中间层、中空六边形环周期层2、面层组成的新型复合双层频率选择表面(FSS)结构件. 其上层FSS的结构参数为中空六边形环边长3.0 mm, 线宽度0.5 mm, 缝隙宽度0.4 mm; 下层FSS的结构参数为中空六边形环的边长3.2 mm, 线宽度0.5 mm, 缝隙宽度1.0 mm. 模拟结果表明: 该复合材料构件具备优良的低频透过性与高频屏蔽性快速转换的特性, 能够获得优异的低通高阻性能, 同时在45°范围内具备优良的角度不敏感性. 最后制备和实验验证得到了0–2 GHz低频段具有95.6%高透过性、同时在7.05–18 GHz高频段具有10 dB 以上屏蔽性能的复合材料构件, 对具有隐身特性的新型滤波电磁功能构件的研制具有重要价值. 相似文献
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利用模式展开和场匹配理论,建立了具有突变结构谐振腔的散射矩阵。在此基础上编制了FORTRAN计算程序,并对Ka波段TE01模回旋速调管的具有突变结构的开放式输出腔进行了数值计算。分析了回旋速调管输出腔的腔体长度和半径变化,以及输出耦合孔的半径和厚度变化对输出腔的品质因数和频率的影响。结果表明:由程序模拟输出腔所得到的计算结果与HFSS软件的结果一致;与冷测实验结果相比,品质因数的相对偏差为1.65%,谐振频率的偏差为10 MHz。 相似文献
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采用交错双栅结构,结合带状电子注,研究了一种工作在140 GHz频段的大功率行波管. 本振模数值计算表明该结构具有良好的色散特性和耦合阻抗.针对所采用的慢波结构, 提出了慢波过渡结构、输入输出耦合器和集中衰减器,保证了行波管的良好工作. 利用三维大信号模拟计算的方法得到的结果显示,当电子注直流功率为5.115 kW,输入信号功率为0.1 W时, 所研究的行波管能在132-152 GHz范围内提供大于300 W的峰值功率,其中在138 GHz时得到最大功率546 W, 对应增益为37.37 dB.当在0.027-0.46 W内调节输入信号功率,可以保持该行波管在128-152 GHz 频带内得到大于440 W的峰值功率,对应的电子效率大于8.6%. 结果显示该行波管将在大功率短毫米波领域具有重要意义和潜在应用价值. 相似文献
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为了研究史密斯-帕塞尔自由电子激光的输出频率和光栅槽深、光栅槽长、光栅槽宽的关系,对于基于矩形光栅的史密斯-帕塞尔自由电子激光利用粒子模拟软件进行模拟和理论分析。首先,利用粒子模拟软件模拟对于基于矩形光栅的史密斯-帕塞尔自由电子激光进行了研究,发现史密斯-帕塞尔自由电子激光的输出频率随光栅槽深、光栅槽长、光栅槽宽的增大而减少。接着,对史密斯-帕塞尔自由电子激光的光栅槽进行了理论分析,发现每个光栅槽都可以等效为一个LC谐振电路,并发现在史密斯-帕塞尔自由电子激光中存在两种辐射,一种是史密斯-帕塞尔辐射,另一种是LC振荡辐射。最后,对光栅槽的LC振荡辐射进行了估算,发现史密斯-帕塞尔自由电子激光输出频率的模拟值与光栅槽的LC振荡辐射估算值的数量级均为102 GHz,且变化规律上一致。据此推测决定史密斯-帕塞尔自由电子激光输出频率的应该是光栅槽,而不是谐振腔。 相似文献
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Study of a rectangular coupled cavity extendedinteraction oscillator in sub-terahertz waves 下载免费PDF全文
An extended interaction oscillator (EIO) generating 120 GHz wave in sub-terahertz waves is studied by using the three-dimensional electromagnetic simulation software CST and PIC codes. A rectangular reentrant coupled-cavity is proposed as the slow-wave structure of EIO. By CST, the circuit parameters including frequency-phase dispersion, interaction impedance and characteristic impedance are simulated and calculated. The operation mode of EIO is chosen very close to the point where βL = 2π with corresponding frequency 120 GHz, the beam voltage 12 kV and the dimensions of the cavity with the period 0.5mm, the height 3mm and the width 1.4mm. Simulation results of beam-wave interaction by PIC show that the exciting frequency is 120.85 GHz and output peak power 465 W with 12-period coupled-cavity with the perveance 0.17 μP. Simulation results indicate that the EIO has very wide range of the operation voltage. 相似文献
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The results of computer simulation of a two-stage millimeter-wave klystron oscillator are reported. The oscillator consists of two closed-loop floating-drift-tube klystrons with the output cavity of one klystron connected to the input cavity of the other and vice versa. It is shown that 200-W oscillations at a frequency of 95 GHz can be reached by optimizing the coupling coefficient between the cavities and the loaded Q factor. 相似文献
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针对高功率微波对毫米波引信的前门耦合效应问题,利用电磁仿真软件对某型毫米波调频连续波引信模型进行辐照试验,并与引信前端限幅电路结合进行联合仿真。在此基础上,继续设计正交试验,对信号参数影响水平进行分析。通过仿真试验发现,在高功率微波信号频率和引信工作频率对准的情况下,辐照场强峰值为60 kV/m时,天线末端耦合电压最大可达188 V;当辐照场强峰值为40 kV/m时,改变辐照信号特征参数,发现长脉宽信号更容易导致限幅器的热击穿效应;信号上升时间会影响天线末端耦合电压波形复杂程度,当信号峰值、脉宽一定时,上升时间为5 ns的输入信号导致的尖峰泄漏电压约为5.94 V,而当上升时间为0.1 ns时,尖峰泄漏电压为18.4 V,并且限幅电路更快达到饱和状态;通过正交试验发现,信号上升时间对尖峰泄漏峰值电压的影响最大,信号峰值对其的影响次之。 相似文献