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1.
理论计算和分析了微波圆柱同轴谐振腔高阶横磁(TM)模式的系列关联参数.研究发现:与圆柱腔相比, 同轴谐振腔的TMn10模式有较大的模式间隔,即工作模式能够远离非工作模式的干扰,这有利于保持器件稳定的频率和功率;在保持腔长不变、腔横截面外半径取特定值时,腔内电场峰值位置的轴向特性阻抗随内径的变化存在极大值;在高频段可以采用任意大横截面的腔体结构和任意阶的模式.计算结果与仿真结果相一致.
关键词:
高阶横磁模式
圆柱同轴谐振腔
特性阻抗
多注速调管 相似文献
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根据电磁场理论设计了S波段TM610高次模圆柱谐振腔。运用HFSS,ISFELD3D, CST-MS及MAFIA软件计算了该谐振腔中TM610及其附近模式的电磁场分布、谐振频率及模式间隔。计算表明:TM610模式的电磁场集中在漂移管头周围的区域,谐振腔中心处无电磁场分布。根据TM610模式的特点,采取了在腔中心放置铁氧体微波吸收材料的方法来抑制杂模。HFSS模拟表明:腔内吸收材料可消除TM510模式外大部分杂模的影响。采用了在主谐振腔外加耦合吸收腔的方法来抑制TM510模式,该吸收腔基模TM010的谐振频率等于TM510的谐振频率。模拟表明:TM510模式的大部分能量可以被吸收腔内的铁氧体材料衰减掉,Q值从15 604下降到571。 相似文献
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利用数值方法计算了磁绝缘线振荡器(MILO)主慢波结构谐振腔和扼流腔的谐振频率和场分布,得出慢波结构谐振腔谐振频率的一些变化规律:随着叶片内半径的增大、叶片外半径的减小、叶片周期的减小以及叶片间距的减小,谐振腔TM01模式截止频率升高;而阴极半径的变化对截止频率几乎无影响。当主慢波结构腔内半径为4.6cm,扼流腔内半径为4.2cm,阴极半径为3cm时,MILO工作在3.“4.4GHz频率范围,扼流片可以阻止微波功率向脉冲功率源泄漏,这有利于提高器件微波输出的效率; 相似文献
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同轴回旋管中不可避免发生内导体倾斜。主要研究了内导体倾斜对特征根、Q值、谐振频率、横向电场、模式竞争和电子效率的影响,并以170 GHz TE31, 12内开槽同轴回旋管作为实例对内导体倾斜理论进行验证。结果表明,特征根和Q值随倾角θ增大而略微增加。在0~0.5°范围内,当θ稍微增大时,电子互作用效率稍微减少。如果θ增加到1.3°,则由于模式竞争严重,且横向电场畸变严重,电子互作用效率降低到只有5%。受内导体倾斜的影响, 随着θ增加,无论热腔还是冷腔,谐振频率都稍微增大。 相似文献
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建立了C波段磁绝缘线振荡器开放腔模型,通过监测宽带激励源的响应计算出开放腔的谐振频率和有载品质因数。用时域有限差分法计算了不同的径向位置一个周期内的径向电场随纵向距离的变化。计算表明:0~4.1 cm区电场很小但不为零;4.1~11.5 cm区域电场呈现驻波特性;在11.5~20 cm区域电场分布比较复杂,表现两个性质,一是驻波场过渡到行波场,二是从周期性加载圆柱谐振腔的TM00模过渡到同轴线的TEM模;在20~36.85 cm区域电场每经过1/4周期向右传播1/4波长,表现出行波特性。由此根据该计算结果将开放腔中的场从左到右分成4个区:截止区、驻波区、过渡区和行波区。最后根据定义计算了开放腔的固有品质因数和有载品质因数。 相似文献
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多注相对论速调管利用多注电子注并行工作,各电子注在传输过程中彼此独立,利于提高注波互作用效率,抑制杂模振荡。分析多注相对论速调管的小信号理论,从谐振腔内电场的场形函数出发确定了不同腔体结构的耦合系数的计算方法,得到了不同电子注形状、注数时的基波电流分量轴向变化过程,并进行模拟验证。结果表明:同轴谐振腔的间隙耦合系数要大于圆柱腔的间隙耦合系数,采用同轴谐振腔更有利于注波互作用;电子群聚过程与每注电子注的势能密切相关,提高电子注数目有助于得到更大的基波电流分量。在电子注电压600 kV、电流5 kA、间隙电压30 kV的条件下,输入腔后的基波电流分量达800 A。 相似文献
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本文给出了确定任意纵剖面形状的缓变波导开放谐振腔内各模式谐振频率的普遍关系式。探讨了腔内各谐振模式场的纵向分布函数的求解方法。具体地分析了鼓形腔和双圆锥腔,分别推导了这两种开放腔各模式的固有谐振频率公式以及场的纵向分布函数。理论分析与实验结果甚为一致。 相似文献
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Characteristic equation for the cylindrical TM010-microwave plasma cavity is given. Analytical expression and perturbation formula for the resonant frequency of TM010 mode dependence of plasma are derived. A comparison between exact and approximate solution shows that the perturbation theory can be used accurately to analyze the detuning of the cavity caused by microwave plasma with a tolerance less than 5%. 相似文献
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设计了外Q值较小,工作于高阶横磁TM310模的X波段速调管单间隙同轴输出谐振腔。用微波等效电路理论计算了高阶横磁TM310模情形六个漂移管的等效间隙中心位置,由此计算腔内等效间隙中心到输出波导内横向膜片的等效长度。以MATLAB编程计算得到同轴谐振腔TM310模式加载矩形波导滤波器输出回路的间隙阻抗,其结果与传统冷测模拟法计算结果吻合。验证了等效长度计算方法的正确性,用于圆柱腔基模的传统微波等效电路理论能用于分析同轴谐振腔高阶横磁模式输出回路,且比传统的冷测模拟法及场分析法更为快捷。 相似文献
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Wave growth rate in a cylindrical metal waveguide with ion-channel guiding of a relativistic electron beam 下载免费PDF全文
This paper addresses the formulae and numerical issues related to the possibility that fast wave may be grown when a relativistic electron beam through an ion channel in a cylindrical metal waveguide.To derive the dispersion equations of the beam-wave interaction,it solves relativistic Lorentz equation and Maxwell’s equations for appropriate boundary conditions.It has been found in this waveguide structure that the TM 0m modes are the rational operating modes of coupling between the electromagnetic modes and the betatron modes.The interaction of the dispersion curves of the electromagnetic TM 0m modes and the upper betatron modes is studied.The growth rates of the wave are obtained,and the effects of the beam radius,the beam energy,the plasma frequency,and the beam plasma frequency on the wave growth rate are numerically calculated and discussed. 相似文献
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Computer Simulation of a 5.7GHz, 110kW Transit-Time Oscillator 总被引:1,自引:0,他引:1
K. G. Kostov J. J. Barroso 《International Journal of Infrared and Millimeter Waves》1998,19(11):1513-1521
A high-power transit-time oscillator producing 110kW at 5.7GHz in the TM010 cavity mode is described. The device comprises a temperature-limited diode electron gun operating at 40A in the range from 28kV to 35kV and an intermediate coaxial cavity from which the microwave power is extracted through a TEM coaxial guide. The diode serves also as a resonant cavity, where electromagnetic oscillations are grown from noise. The effect of the applied voltage on both the output microwave power and the instability saturation time has been investigated leading to an optimal diode voltage of 33kV. 相似文献
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Hebi Zhang 《International Journal of Infrared and Millimeter Waves》2000,21(2):201-207
A novel axially modulated, annular electron beam cusp-injected, slowly varied section opened cavity, hybrid-magnicon amplifier had been proposed I once. The hybrid-magnicon has wavelength up to millimeter wave bend. The while its non-self-consistent non-space-charge nonlinear numerical calculation method was discussed. But due to bunch effect is changing uniform distribution state of the annular electron beam in the driver cavity, and then dynamic force balances of the beam is changing. Therefore, besides the interaction force between electron beam and the rotating TMn10 mode electromagnetic field also must consider the electromagnetic force of current density and the action force between the space-charges and the action force of the charge density grade, et al. effect. For some problems of theory, this report try discuss from Maxwell Equations. 相似文献
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M. S. Sodha Prayag Chandra V. K. Tripathi 《Applied Physics A: Materials Science & Processing》1976,11(3):299-301
Using an appropriate expression for the field-dependent dielectric constant of a collisionless plasma, we have studied the
field distribution of the TM01 mode in a cylindrical waveguide. The wave equation has been solved by a Runge Kutta technique. It is seen that on account
of redistribution of carriers from the high-field regions to low-field regions a beam of frequency lower than the average
plasma frequency can be transmitted if its power is high.
Work supported by NSF 相似文献
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Three dual mode microwave apparatus (one using S ‐band and two using X ‐band) have been developed to determine ambipolar diffusion and electron‐ion recombination rates under conditions such that Tgas = 300K and Te is varied from 300 K to 6300 K, in the afterglow period of the dc glow discharge. TheTM010 cylindrical cavity (in S ‐band) and TM011 open cylindrical cavity (X ‐band) are used to determine the electron density during the afterglow period and a non‐resonant waveguide mode is used to apply a constant microwave heating field to the electrons. To test the properties of the apparatus the neon afterglow plasma has been investigated. At Te = 300 K a value of α (Ne+2) = (1.7± 0.2) × 10–7cm3/s is obtained which is in good agreement with values of other investigators. Also similar variations of α as T–0.4e (S ‐band) and as T–0.42e (X ‐band) obeyed over the range 300 ≤ Te ≤ 6300K are in good agreement with some other previous measurements. The simplicity of the X‐band microwave apparatus also allows the measurements of the gas temperature dependency and the study of electron attachment and may be used simultaneously with optical or mass spectrometry investigations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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F. Consoli S. Barbarino L. Celona G. Ciavola S. Gammino D. Mascali 《辐射效应与固体损伤》2013,168(10-12):467-475
Both theoretical and numerical electromagnetic analyses about the modes inside the cylindrical cavity of superconducting electron cyclotron resonance ion source (SERSE) have been performed. Modes close to 14, 18 and 28 GHz frequencies, usually employed in SERSE operating conditions, have been calculated in vacuum and when the chamber is filled with a uniform non-collisional plasma at different electron densities. To consider the holes present in the chamber flanges, a numerical approach has been used, by means of the HFSSTM electromagnetic simulator, for the first mode in the cavity. Modes in a plasma-filled cylindrical cavity with holed bases have full width half maximum bandwidths larger with regard to the closed cavity in vacuum, and it leads to an increased mode frequency overlap. A monochromatic electromagnetic wave feeding this cavity can, in principle, excite different modes. Further investigations about the coupling between the SERSE cavity and its feeding waveguides have to be performed. 相似文献
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从麦克斯韦方程和流体理论出发,推导了填充磁化等离子体慢波结构的基本方程.在大磁场情况下,对等离子体填充盘荷波导的色散特性和耦合阻抗作了研究,结果表明填充等离子体使色散曲线上移,耦合阻抗提高.等离子体填充产生出模式谱非常丰富的周期性低频等离子体模式(TG模式).当等离子体密度增加到一定程度后,场模TM01模的频率范围和TG01模的频率范围相近,两个模式互相耦合产生出新的混合模G1,G2.如果相对论行波管工作在混合模上,将会产生新的工作机理.
关键词:
盘荷波导
等离子体填充
色散特性
相对论行波管 相似文献