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本文提出用图形逼近和取尺寸上、下限值的几何平均值的方法,计算椭圆外导体-矩形内导体同轴线特性阻抗。矩形截面内导体的内切共焦椭圆和外接共焦椭圆,通过保角变换,变成同心圆。矩形变成近于矩形的闭合曲线,二同心圆分别为它的最小值和最大值,取二者的几何平均值,与同轴椭圆截面外导体同时变成的同心圆,构成一个标准同轴线,得到了特性阻抗公式。并由此推导出椭圆外导体-微带内导体、圆形外导体-方形内导体、圆形外导体-矩形内导体及圆形外导体-微带内导体等各种同轴线的特性阻抗的初等函数表示式。给出了上述几种同轴线的特性阻抗准确数值。
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Humberto César Chaves Fernandes Eduardo Amorim Martins de Souza Idalmir de Souza Queiroz Júnior 《International Journal of Infrared and Millimeter Waves》1994,15(6):1001-1014
The theory and numerical results are presented to the effective dielectric constant and characteristic impedance of bilateral and unilateral finlines with metallization thickness. The full wave analysis of the transverse transmission line — TTL method is used to determine the electromagnetic fields of the structure in Fourier transform domain — FTD. Applying the suitable boundary conditions and the moment method, a homogeneous matrix system is obtained and the effective dielectric constant is extracted. The characteristic impedance is obtained using the relation between the voltage in slot and the transmitted power.Computational programs are developed to obtain numerical results to the effective dielectric constant and characteristic impedance. 相似文献
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Naichang Yuan Chengli Ruan Weigan Lin 《International Journal of Infrared and Millimeter Waves》1993,14(4):873-884
A Novel multiconductor elliptic cone microstrip lines are rigorously analyzed under the assumption of quasi-TEM mode. The Maxwell's capacitance matrix and characteristic impedance matrix are determined using the method of coordinates trnasformation and conformal mapping 相似文献
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Humberto César Chaves Fernandes Eduardo Armorim Martins de Souza Idalmir de Souza Queiroz Jr 《International Journal of Infrared and Millimeter Waves》1995,16(1):185-200
In this study, the effect of the metallization thickness in finlines on semiconcuctor substrate is researched. The propagation parameters are computed to measure the inluence of the metallization. The theory and numerical results are presented to the propagation constant and characteristic impedance of the bilateral and unilateral finlines. The full wave analysis of the transverse transmission line — TTL method is used to determine the electromagnetic fields of the structure in Fourier transform domain — FTD. Applying the suitable boundary conditions, the moment method and expanding the fields in a set of suitable bases functions, a homogeneous matrix system is obtained and the propagation constant is computed. The characteristic impedance is obtained using the relation of the voltage in the slot and the transmitted power by the structure.Computational programs are developed to obtain numerical results to the propagation parameters composed by the propagation constant and characteristic impedance.This work received financial support by CAPES and CNPq. 相似文献
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开关振荡器是宽带高功率电磁脉冲的重要产生方式之一,以开关激励同轴振荡器为例,采用理论计算和电磁仿真为主要手段,从传输线特性阻抗与开关振荡器储能、传输线特性阻抗与天线阻抗关系及传输线特性阻抗和开关导通阻抗关系三个方面进行了研究。研究结果表明:传输线阻抗越小,振荡器储能越高;天线阻抗与传输线阻抗比值越大,输出信号品质因数越大,频谱上能量越集中,带宽越小,能量效率随比值增大呈现先增大后减小趋势;传输线特性阻抗很小时,开关阻抗对输出振荡信号影响增大,此时随特性阻抗减小,输出信号中心频率降低,品质因数减小,频谱上能量分散,带宽较宽。 相似文献
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研究了一种新型低电感花瓣形磁绝缘传输线的冷腔特性。该传输线构型的横向剖面的真空部分由12个类似花瓣形状的周期组成,而每个周期又由平行板和同轴圆弧两种基本传输线构型组成。该构型的整体轮廓有效增加了电极面积,使得传输线的电感大大降低,从而实现使用单层磁绝缘传输线即可获得较低的阻抗,规避了多层汇流结构带来的复杂的PHC结构和磁零位区损失问题。首先,分别计算出两种基本构型单元的电磁场分布、电感、电容和阻抗;而后,再整体计算分析出花瓣形磁绝缘传输线的电磁特性参数;同时,还通过数值模拟来分析该传输线的冷腔特性,获得了该传输线的阻抗值及电磁场分布,并将数值模拟结果与理论计算值进行了对比分析,结果验证了理论计算方法的正确性。 相似文献
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A conformal transformation for the analysis of a transmission line consisting of a cylindrical conductor placed opposite a slit in an infinite flat plate is developed. The approximate and exact expressions in closed- form of the characteristic impedance for the proposed line based on assuming only a quasi-TEM mode propagating in the line are as exact as the conventional one cited. 相似文献
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A new formula connecting the elliptic 6j-symbols and the fusion of the vertex-face intertwining vectors is given. This is based on the identification of the k fusion intertwining vectors with the change of base matrix elements from Sklyanin’s standard base to Rosengren’s natural base in the space of even theta functions of order 2k. The new formula allows us to derive various properties of the elliptic 6j-symbols, such as the addition formula, the biorthogonality property, the fusion formula and the Yang-Baxter relation. We also discuss a connection with the Sklyanin algebra based on the factorised formula for the L-operator.Mathematics Subject Classification (2000). 33D15, 81R50, 82B23 相似文献
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通过本征方程研究了工作在太赫兹(THz)频段的高次模同轴谐振腔,讨论了TMm, 1, 0模,TMm, 2.0模与TMm, 1, 1模的谐振频率与腔体的几何参数之间的关系,并给出了工作模式的选择依据。在此基础上,提出了一种新型的0.3 THz TM10, 1, 0模同轴耦合腔链,使用等效电路模型和CST-MWS软件对耦合腔链的色散特性、特征阻抗和电场分布等冷腔特性进行了分析和仿真,并着重分析和总结了耦合腔链的几何参数对色散特性和特征阻抗的影响。研究结果表明:对于工作在THz频段的高次模同轴耦合腔链,采用TM10, 1, 0模为工作模式是合理的选择; 工作于2π腔模的0.3 THz TM10, 1, 0模同轴耦合腔链具有较大的特征阻抗,但模式间隔较小,因此可将其应用于窄带太赫兹扩展互作用器件; 增大高次模耦合腔链的耦合槽张角是增大模式间隔的最佳途径。 相似文献
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The complex permittivity and permeability of composites filled with Fe-based microwires are measured in a coaxial line at frequencies from 0.01 to 10 GHz.The samples under study consist of closely packed wire sections with various orientations relative to wave vector. The composites, where the wires are collinear to the coaxial axis, are found to be low permeable. Their permittivity has frequency dispersion governed by the length of the wire and its linear impedance. The middle section of the wire has higher impedance than that of the end sections where the regular domain structure is distorted. Magnetic bias parallel to the wire axis affects the linear impedance and parameters of dielectric absorption of a composite, the effect is proportional to bias strength. The samples of a coil-type structure, where the wires are wound around the coaxial axis, display the intensive magnetic absorption attributed to the domain wall motion. The absorption takes place in the megahertz band, at microwaves the permeability is close to unity. The microwave properties of diluted composites filled with randomly oriented permeable wires are discussed. 相似文献
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Guo Jun Yan Yang Meng Lin 《International Journal of Infrared and Millimeter Waves》2005,26(5):657-667
The dispersion relation of a corrugated—wall resonator with an inner coaxial structure has been analyzed as well as the effects of the corrugation period, amplitude and the radius of the coaxial structure on it. Furthermore, we got an output power of 2.1GW at frequency 11.09GHz in a non-uniform slow wave structure by using the PIC simulation software—MAGIC. 相似文献
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为了揭示设备互连电缆在连续波电磁辐照条件下的耦合响应规律,以典型射频同轴电缆为受试对象,将电缆终端连接的设备(系统)等效为负载,通过对其进行连续波电磁辐照效应试验研究,分析了受试电缆长度、终端负载状态等对同轴电缆终端负载响应规律的影响。结果表明:同轴电缆对电磁辐照响应具有选频特性,终端负载响应电压的峰值出现在电缆相对长度为1/2整数倍的频点;同轴电缆受到连续波电磁辐照后,感应皮电流通过转移阻抗转化为芯线与屏蔽层之间的差模感应电压,而这一感应电压源的内阻就是同轴电缆的特性阻抗;同轴电缆终端负载阻值的变化不会对其连续波辐照响应曲线的变化规律产生影响,终端负载与等效感应电压源内阻上的电压响应满足分压原理; 同轴电缆皮电流处于谐振状态时,两波节之间的分布感应电压同向,可等效为一个感应电压源,对同轴电缆终端负载响应起直接作用的电压源是最靠近终端负载的等效感应电压源。 相似文献