Equivalent circuit parameters of an aperture coupled open resonatorcavity

In this paper, we use modified form of Bethe's small hole coupling theory to compute equivalent circuit parameters of an aperture coupled open resonator cavity. The open resonator cavity is composed of spherical mirrors of circular cross section. The cavity is coupled to a rectangular waveguide by means of a common hole in the mirror and the shorted end wall of the rectangular waveguide. Closed form expressions have been obtained for the equivalent circuit parameters. Experiments conducted in the W-band frequency range show good agreement with theory when an experimentally estimated correction to the transmission coefficient is applied for the thickness of the coupling holes     

W波段带状注耦合腔慢波结构行波管的设计与冷测

对W波段三槽梯形线耦合腔慢波结构(包括大功率输入输出耦合器和射频窗)的加工和冷测进行了研究。此慢波结构由一个矩形波导耦合器馈电,该耦合器由放置在输入腔短边上的三阶阶梯变换矩形波导组成。首先,利用仿真方法研究了慢波结构的色散、互作用阻抗、传输特性和注-波互作用。结果表明,采用三槽梯形线耦合腔慢波结构的行波管能够在91~96 GHz的频率范围内提供大于1000 W的饱和输出功率,并且在94 GHz频点,饱和输出功率最大,可以达到1125 W。其次,采用高精度数控铣床加工出三槽梯形线慢波结构,并将其固定在非磁性不锈钢外壳中。文中给出了带有耦合器和射频窗的三槽梯形线慢波系统的测试结果,表明在90 GHz到100 GHz的频率范围内,S11<-10 dB。因此,三槽梯形线慢波结构在W波段大功率行波管方面具有应用前景。     

矩形耦合腔行波管的研究

为了得到高功率、高频率、大带宽的微波源,运用微波仿真软件CST对矩形耦合腔行波管这一新型的大功率器件进行了粒子模拟,得到了23．7kw的峰值输出功率,并且分析了行波管的工作电压与慢波系统的腔体数量对行波管工作特性的影响。结果表明,矩形耦合腔行波管具有较高的功率承载能力。     

TM310高次模圆柱形谐振腔耦合矩形波导输出回路研究

设计了适用于多注速调管,工作在TM310高次模圆柱形谐振腔耦合矩形波导输出回路,其工作中心频率为7 585.3 MHz,计算了腔体内各漂移管间隙阻抗的频率特性,并分析了输出回路的输出带宽.研究结果表明: 在相同频率条件下,采用圆柱形TM310工作模式的谐振腔体积将是采用圆柱形TM010工作模式谐振腔体积的7倍;TM310高次模圆柱形谐振腔耦合矩形波导后,各漂移管特性阻抗与耦合前相比有稍微变化,但耦合后各间隙特性阻抗非常接近;反射系数相位法及等效电路法计算输出腔外观品质因数分别为为154和160,输出中心频率7 585.263 MHz,比耦合前腔体谐振频率降低26.525 MHz,输出带宽约为3%,因此,该类型输出回路比较适合用作高射频段的窄带多注速调管.     

Computation of external circuit impedance of active devices in amillimeter wave harmonic power combiner

In this note, the external circuit impedance looking outside from two active devices, which are abreast mounted in the rectangular waveguide cavity of a millimeter wave harmonic power combiner, are analyzed and computed by strict field analysis method and the technique uniting Galerkin method with Collocation method. The numerical results are very useful to design the millimeter wave harmonic power combiner and develop its CAD     

Characterization of two coupled radial line transformers in dual-diode millimeter wave oscillators

Two mutually coupled radial line transformers mounted in a common rectangular waveguide of dual—diode millimeter wave oscillator are characterized by a hybrid technique based on Galerkin's method combined with collocation technique. The external circuit impedances looking outside from each of two active devices are calculated. A large number of numerical results of the external circuit impedances as a function of the structural parameters have been obtained. Some original conclusions have been made, which are helpful to the design and the adjustment of the dual—diode oscillators.     

Transverse Modal Analysis of Printed Circuit Transmission Lines

Dispersion characteristics of finned rectangular waveguides, finlines, shielded slotlines, shielded microstrip and striplines, and shielded two-coupled slotlines and striplines are formulated by the transverse modal analysis method. A rectangular cavity is formed by placing two electric walls transverse to a uniform transmission-line system. Considering that the wave propagation is in the direction transverse to the transmission line and to the dielectric discontinuities, the rectangular cavity can be viewed as multiple rectangular waveguide sections joined by the discontinuities. The rectangular waveguide modal analysis technique is readily applicable to obtain the dispersion characteristics by matching the boundary conditions at the discontinuities interface. Numerical solutions are obtained using Galerkin's method, and the results are compared with several numerical techniques for various transmission-line systems.     

基于时频分析的电磁脉冲耦合效应研究*

为了解高功率电磁脉冲对电子系统的干扰与毁伤影响,利用基于Wigner鄄Ville 分布的时频分析方法对耦合进电子系统内部的电磁信号进行了特征分析。与单独的时域分析和频域分析相比,时频分析不仅能够得到信号的时域特征和频域特征,还能同时得到信号各频率分量随时间的变化情况。利用瞬态极化时频分析,进一步得到信号极化状态在时频域的分布。仿真结果表明,时频分析得到的结果更全面详细,可以根据时频分析得到的信号特征更加准确地指导电子系统的高功率电磁脉冲防护加固。     

Electric and Magnetic Coupling through Small Apertures in Shield Walls of Any Thickness

A method is presented for evaluating the coupling between two identical resonant cavities coupled by a small aperture in a plane common wall of arbitrary thickness. The coupling is related to the frequencies of the symmetric and asymmetric modes of oscillation of the coupled cavity structure, and a variational technique is used to determine those frequencies. The method is applied to circular and rectangular apertures, and it is shown that the coupling is separable into electric and magnetic terms. The results enable theoretical solutions to be obtained for the electric and magnetic polarizabilities of circular and rectangular apertures in walls of zero thickness, and equivalent polarizabilities to be obtained when the wall thickness is nonzero. Curves of numerical values are given for circular and rectangular apertures. With zero wall thickness, the results obtained are the same as those of Bethe for a circular aperture and give good agreement with Cohn's experimental results for rectangular apertures.     

太赫兹扩展互作用振荡器的矩形耦合腔特性研究

本文选用矩形耦合腔作为太赫兹扩展互作用振荡器(EIO)的慢波结构,鉴于其结构的复杂性,采用等效电路方法计算其色散.详细研究了腔体和耦合槽的电路参数,计算了不同结构尺寸、圆形和矩形电子通道的0.12THz和0.225THz慢波结构的色散特性.并采用专业电磁软件,研究了不同结构参数下的色散特性、耦合阻抗和特征阻抗.通过对色...     

有内置薄板腔体的HEMP屏蔽效能研究

在HEMP(高空核电磁脉冲)平面波照射下,依据传输线理论和波导理论,结合电路原理,分别建立了HEMP在金属腔内传播时的等效电路模型和信号流图,得到了腔体各部分的等效阻抗以及HEMP 在腔体内传播过程中的传输矩阵和散射矩阵。采用了传输线法(TLM)和广义Beam-Liu-Tesche(BLT)方程法两种快速算法计算有内置薄板的开孔矩形金属腔的屏蔽效能,与仿真计算进行了对比,验证了扩展算法的准确性,并分析了内置薄板的宽度和位置对腔体屏蔽效能的影响。结果表明:两种快速算法均能准确地计算腔体的屏蔽效能;内置薄板越宽,且越靠近中央位置,腔体的屏蔽效能越高,谐振频率越大。研究所得结论可以为电子设备的HEMP防护提供重要的理论依据。     

The variational method and the method of moments in the problem of plane wave scattering by a rectangular cavity in an impedance screen

The problem of electromagnetic plane wave diffraction by a rectangular cavity in an impedance screen is solved. The problem is reduced to solution of a Fredholm integral equation for the field function in the aperture. The equation has a symmetric kernel. Expressions for the angular distribution of the scattered far-field are obtained by the method of moments and the variational method. Numerical results are analyzed and compared.     

Analysis and experiment of substrate integrated waveguide cavity of four sidewalls of cylinders and solid top and bottom walls

Given in this paper are the equivalence formulas to convert the substrate integrated rectangular waveguide (SIW) resonant cavity of cylinder sidewalls (and solid top- and bottom-walls) to its equivalent rectangular wavguide cavity of solid sidewalls. The equivalence is analytical, therefore it should be excellent as long as the radius of the cylinders and their separation are small in terms of wavelength. Two prototypes are fabricated to demonstrate the validity of the equivalence formula. Excellent agreement of the measured and analytical resonant frequencies of TE₁₀₁ mode has been observed in the substrate integrated rectangular waveguide resonant cavity, indicating the accuracy of the proposed equivalence theory. Such equivalences are convenient for the design of small waveguides, of millimeter wave, in a multilayer circuit structure, such as the LTCC.     

Long rectangular patch antenna with a single feed

Radiation characteristics of a long rectangular patch antenna excited by a single feed are investigated. The equivalent circuit of the patch including the feed line section is developed. It is found theoretically that a single feed long rectangular patch supports a leaky traveling wave along the length of the patch. The complex propagation constant of the traveling wave is estimated by solving the wave equation with impedance boundary conditions. Radiation patterns of the antenna are obtained using the principle of equivalence. Various radiation characteristics of center-fed and end-fed long patch antennas are presented     

基于方形腔耦合金属波导结构的全光等离子体开关

提出了一种新型的方形腔耦合金属波导结构,该结构由两个相互平行的矩形金属波导和一个内嵌可连通的方形谐振腔构成。利用方形谐振腔局域表面等离子体实现带阻滤波特性,并通过多路复用实现双端口全光等离子体开关。采用时域有限差分方法(FDTD)研究了方形腔的边长、折射率和谐振距离对强透射特性的影响。结果表明,基于方形腔耦合金属波导结构的光开关在工作中具有较好的阻带特性和透射特性,其最大透射率可达92%,最小阻带透射率达0.2%,工作波长范围为607~785nm。     

矩形π-TM310 双间隙腔加载同轴滤波器型宽带输出电路研究

本文提出了矩形π-TM310 双间隙腔加载同轴滤波器型宽带输出电路,并对其可行性进行了论证,对高次模双间隙腔中非工作模式的干扰程度和同轴线输出电路的功率容限等重要问题做了定量分析。我们通过调整矩形双间隙腔的长宽比例并采用凹入结构,明显扩大了π-TM310模与相邻非工作模的频率间隔,有效抑制了非工作模式的干扰;又采用了非常规的电子注孔布局,使各个电子注孔的特性阻抗更均匀,而且在加载同轴滤波器之后仍然很均匀。研究结果表明,经过优化设计的矩形π-TM310 双间隙腔加载同轴滤波器型输出电路具有很宽的输出频带,在X波段相对带宽达到14%左右。但由于π模双间隙腔与同轴线的耦合口较小,而且该处还有短路销钉,导致其输出功率容限较低,约为几百kW。因此,该类输出电路比较适合于X波段或更高频段的中功率宽带多注速调管。     

Electromagnetic penetration into a rectangular cavity with multiplerectangular apertures in a conducting plane

Electromagnetic wave penetration into a rectangular cavity with multiple rectangular apertures is studied. The Fourier transform and the mode matching method are used to obtain simultaneous equations for the modal coefficients. The simultaneous equations are solved to represent the cavity field in series forms, which are suitable for numerical computations. Numerical computations are performed to investigate the field penetration into a cavity in terms of the shielding effectiveness for a various geometry     

PCB电路电磁脉冲效应混合仿真方法

电磁脉冲作用于屏蔽腔内的微带线电路的过程十分复杂。目前已有的研究存在局限,缺少将场分析与电路分析结合起来的研究方法。通过一个混合模拟方法计算了电磁脉冲辐照下的含屏蔽腔的微带线电路上的耦合电压。该方法通过建立腔体与微带线的电磁拓扑模型,利用BLT方程计算得到电磁脉冲在微带线上的耦合电压,结果表明电场强度为1 000 V/m的电磁脉冲会在微带线终端产生1.5 V左右的耦合电压。通过电路仿真软件仿真计算了外辐射场对电路工作状态造成的影响,外辐射场在300 V/m时会影响信号放大电路的正常工作。     

一种用于谐波倍增回旋放大器的耦合腔互作用电路

该文提出了一种用于回旋管放大器的新型耦合腔互作用电路模型。基于Ansoft HFSS高频计算软件,分析计算了矩形波导TE□10模输入,圆波导TE○01模输出模式转换系数随几何参数和工作频率的变化关系,讨论了结构变化对模式选择和抑制的作用。HFSS的模拟计算结果表明,对TE□10到TE○01转换,TE○01模能够稳定工作,且能量转换效率最大可以大于97%,－3dB带宽最大可以大于327MHz,是谐波倍增回旋行波放大器的一种可选输入耦合结构。