共查询到18条相似文献,搜索用时 46 毫秒
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针对THz波段介质涂敷空芯金属圆波导传输特性的精确分析问题,基于波导中场方程及边界条件建立关于传播常数的特征方程,并且采用改进的Muller法求解特征方程得到涂敷圆波导主模HE11模的传播常数。计算中对THz波段的非理想导体电导率采用经典弛豫效应模型。仿真结果表明:内径为1.8 mm的银波导,当聚苯乙烯涂敷层厚度为17 m时,HE11模在1.5~3.0 THz的衰减常数在1 dB/m以下,且具有较好的色散特性;内径为2.2 mm的银波导,在2.5 THz时其衰减常数随涂敷层厚度的增加先增大后减小,且存在最佳介质涂敷层厚度,可实现THz波低损耗传输。 相似文献
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理论分析了介质镀膜空芯光纤在THz频段的传输特性,得出了该光纤的特征方程及模式分布。利用射线光学原理计算了介质膜材料为聚酰亚胺、介质膜厚度为0.05 mm的光纤的衰减常数随介质膜内直径的变化情况。得出其主模在THz频段的衰减常数小于1 dB/m,该值远小于相同内径的金属圆波导在这一频段的衰减常数。模拟计算了介质膜厚度为0.05 mm、内径为1 mm,金属膜内径为1.05 mm的介质镀膜空芯光纤在0~1 THz的S参数,模拟结果显示该光纤在THz频段有很宽的通带,且在通带内衰减常数小于0.5 dB/m,可用于THz频段电磁波远距离传输。 相似文献
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理论分析了介质镀膜空芯光纤在THz频段的传输特性,得出了该光纤的特征方程及模式分布。利用射线光学原理计算了介质膜材料为聚酰亚胺、介质膜厚度为0.05 mm的光纤的衰减常数随介质膜内直径的变化情况。得出其主模在THz频段的衰减常数小于1 dB/m,该值远小于相同内径的金属圆波导在这一频段的衰减常数。模拟计算了介质膜厚度为0.05 mm、内径为1 mm,金属膜内径为1.05 mm的介质镀膜空芯光纤在0~1 THz的S参数,模拟结果显示该光纤在THz频段有很宽的通带,且在通带内衰减常数小于0.5 dB/m,可用于THz频段电磁波远距离传输。 相似文献
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根据耦合波理论,推导出轴对称渐变波导中, 考虑波导壁损耗时的多模传输时域耦合波方程组,并给出该方程组中各模式间耦合系数的具体表达式。据此编写了渐变波导中多模传输特性数值模拟程序。利用该程序计算了在THz波段圆波导中的模式衰减,在THz波段研究波导中的多模传输特性时,必须考虑波导壁的阻抗损耗影响。数值分析了直波导中的模式耦合问题,从而证实了波导壁有限电导率能产生模式耦合这一耦合机制。介绍了利用该程序数值分析波导耦合器和过渡器中多模传输特性的两个例子,利用该程序可对波导耦合器和过渡器中的多模传输特性进行数值模拟分析,进而对结构进行设计和优化。 相似文献
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根据耦合波理论,推导出轴对称渐变波导中, 考虑波导壁损耗时的多模传输时域耦合波方程组,并给出该方程组中各模式间耦合系数的具体表达式。据此编写了渐变波导中多模传输特性数值模拟程序。利用该程序计算了在THz波段圆波导中的模式衰减,在THz波段研究波导中的多模传输特性时,必须考虑波导壁的阻抗损耗影响。数值分析了直波导中的模式耦合问题,从而证实了波导壁有限电导率能产生模式耦合这一耦合机制。介绍了利用该程序数值分析波导耦合器和过渡器中多模传输特性的两个例子,利用该程序可对波导耦合器和过渡器中的多模传输特性进行数值模拟分析,进而对结构进行设计和优化。 相似文献
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基于电磁模式的色散方程,研究了有损金属圆波导中电磁模式的传输问题.在考虑了损耗层厚度影响的情况下,得到了各模式传输常数的近似解析表达式,此式适用于截止频率附近.通过解析表达式和波导模式色散方程,对衰减常数和相位常数进行了大量数值计算,得到了它们随损耗层厚度、频率以及损耗层电导率的变化规律,两种方法所获得的结果有较好的一致性.研究表明,损耗强度和损耗层厚度的变化会改变波导中电磁模式的色散和简并特性,对于改善高功率回旋行波放大器中注波互作用带宽和模式竞争非常有益.
关键词:
有损圆波导
相位常数
衰减常数
色散方程 相似文献
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V. G. Artjuschenko K. I. Kalaidjian M. M. Mirakian 《International Journal of Infrared and Millimeter Waves》1991,12(10):1175-1185
The results of the efficiency of low-mode excitation of a parallel-plate hollow metallic waveguides (HMW) as a function of beam and waveguide parameters are represented. Coupling of two waveguides is also discussed. 相似文献
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Y. W. Yao F. G. Wu Z. L. Hou Y. Y. Liu 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,58(4):353-360
The transmission and reflection coefficients of two-dimensional semi-infinite solid-solid phononic crystal systems and fluid-fluid
phononic waveguide structures have been investigated. The numerical results show that the transmission spectra for longitudinally
and transversally polarized incident waves are different, and the spectra of the transmission and reflection coefficients
of the semi-infinite system agree well with the band structure. The numerical results show that when a guided wave incident,
localized modes are excited, and different polarities have different coupling efficiencies with the incident guided wave.
At the same time, far from the cutoff frequency, the guided wave couples out of semi-infinite waveguide highly efficiently. 相似文献
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For multimode optical fiber links integrated optical circuits are needed. A first approach has been made by using thick film techniques. We demonstrate an advanced technology using two different materials for the guide. By that we can fabricate high efficient micro optics, like lenses, prisms, beam splitters etc.. To avoid loss within the dielectric guide hollow metallic optical waveguides have been investigated. A 3dB fiber-fiber coupler with an overall loss of 1.3 dB was realized as well as the principle of an integrated prism spectrometer. 相似文献
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Radiophysics and Quantum Electronics - 相似文献
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Propagation of electromagnetic waves in an elliptic waveguide filled with plasma is investigated in elliptic co-ordinates. Dispersion relations for the natural modes of oscillation are obtained. Expressions for power transmitted along the waveguide are obtained as integrals of Mathieu functions. Dispersion relations for circular waveguides are also obtained as limiting cases.One of the authors (S. K. Ghosh) wishes to express his thanks to the University of North Bengal for financial support. 相似文献
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Tian-lin Dong 《International Journal of Infrared and Millimeter Waves》1991,12(12):1451-1459
A simplified mathematical model of two-dimensionally(2D) periodic thin-film wavegmide is proposed and the characteristics of wave propagation are shown to be governed by a five-term recurrence relation with dyadic admittance coefficients. The generalized transverse resonance method can be used to analyze any complicated 2D periodic thin-film waveguide. The dispersion characteristics are described by both approximation analysis and numerical calculation. The theoretical explanation and physical understanding of the effecis of 2D periodic modulation provided by our analysis and resulis can give sound support to the engineering applications. 相似文献
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The basic propagation properties of the silica and silicon subwavelength-diameter hollow wire waveguides have been investigated by comparison. It shows that the silica and silicon subwavelength-diameter hollow wire waveguides have some interesting properties, such as enhanced evanescent field in the cladding, enhanced intensity in the hollow core, and large waveguide dispersion. For the different confinement ability, the enhanced field in the hollow core and cladding of the silica subwavelength-diameter hollow wire is much stronger than that of the silicon one for the same size. 相似文献