Attenuation of a shielded rectangular dielectric rod waveguide

The attenuation coefficient of a rectangular dielectric line enclosed by a rectangular shield is obtained by the use of a rigorous mode-matching method to calculate the required mode field intensity. The cross section of the waveguide is overlaid by a grid, and numerical integration is used to determine the power flow, dielectric, and conductor losses and respective attenuation coefficients. To obtain experimental verification, a length of waveguide was made into a resonator, and measured and calculated Q factors were compared. The results for the E/sup y//sub 11/ mode show how the influence of the shield decreases with distance. This is relevant to the design of dielectric waveguide structures and in filter applications where dielectric resonators are used.     

Dielectric rod antenna based on image NRD guide coupled to rectangular waveguide

A dielectric rod antenna based on an image NRD guide fed by a slot in the broad wall of a rectangular waveguide is proposed. This configuration is developed for the use in the design of an array of this antenna. The antenna characteristics are investigated using the finite difference time domain (FDTD) technique. Measured results at 30 GHz band are presented to validate the numerical analysis.     

Radiation pattern synthesis of dielectric rod waveguide with many corrugations

The radiation pattern synthesis of dielectric rod waveguides with many corrugations is investigated. The guided waves are related in the form of a 2-port circuit and the radiation field is expressed by superposition of waves from the corrugations, so that the radiation pattern can be calculated in a very short time. This expression can be used in a genetic algorithm (GA) to seek the optimum arrangement of corrugations. Synthesized radiation patterns calculated using the 2-port circuit method compare well with patterns synthesised by the FDTD method. Conical beams and spherical sector beams can be synthesized. In the synthesized pattern, there are no unnecessary large lobes such as the grating lobe from a periodic waveguide. The experimental radiation patterns agree well with the synthesized patterns with small difference.     

Computation of the dielectric rod waveguide radiation modes

The continuous mode spectrum of a dielectric rod waveguide is analysed in detail. The validity of the orthogonality relations is proved explicitly and the related normalization factors are computed and presented. The results are compared with existent literature and some discrepancies are noted. A full wave approach is pursued without making use of the “weak guidance” approximantion.     

太赫兹矩形波导与共面波导耦合结构设计

太赫兹（THz）波位于微波与红外光波之间,现有微波和光波段波导技术应用正在向THz波段拓展。但是,由于水汽对THz波的强吸收及制造工艺等原因,THz器件主要是平面结构,而THz源及其传输需要用矩形波导。因此,矩形波导与共面波导之间的转换结构成为决定元件和系统性能的关键部分。该设计利用脊波导进行阻抗匹配及电磁场模式转换,实现THz波矩形波导到共面波导的高效率耦合。结果表明,在0.2~0.4 THz频段内,该转换结构的传输系数(S₂₁)高于?3 dB,可以对THz电磁场进行高效率转换。该结果可用于太赫兹分子探测、太赫兹通信等领域,为0.2 THz以上太赫兹的模式转换提供了一种可行方案。     

Analysis of dielectric rectangular waveguide by modified effective-index method

For dielectric rectangular waveguides an approximate analysis by the modified effective-index method is presented. The results of this method are compared with those of the effective-index method. Our results are generally in good agreement with results of other rigorous approximate analyses.     

用于系统级封装的毫米波介质填充波导的研究

基于不断发展的系统级封装技术,提出了一种用于芯片间高速互连的新型可集成的物理器件:硅基毫米波介质填充波导。文中阐述了该器件的物理原理,采用建模、仿真相结合的方法对该模块进行了结构设计,利用新的设计思路结合半导体工艺解决了毫米波互连结构内部的反射、电压驻波比(VSWR)、信号耦合、准TEM-TE-准TEM转换传输问题以及毫米波互连结构阵列中信号泄露的问题,并利用半导体与MEMS加工工艺加以实现。测试结果表明宽度为680μm的单通道矩形波导,-10 d B带宽为9.8 GHz,相对带宽为12.56%;传输损耗为1 d B/cm,工作频带内相邻波导之间串扰低于-40 d B,可以形成大阵列并进行集成,从而实现芯片间数据的并行传输。     

用Marcatili方法分析矩形介质波导阵列

将Marcatili近似分析方法在应用范围和处理方法上进行了一些改进，并之为扩展的Marcatili方法，根据Floquet理论和该方法，分析了矩形介质波导阵列，推得两个一维周期介质结构的耦合特征方程。数值计算结果表明，在微扰的情况下，特征方程所得的结论与其他方法巳取得的结果吻合很好，它们都能较准确地反应出通带、阻带和空间谐波之间的相互作用等主要周期特性。     

Scattering by a dielectric obstacle in a rectangular waveguide

A method for the computation of S-parameters associated with a rectangular waveguide with a rectangular or cylindrical obstacle of arbitrary complex scalar permittivity is presented. The method uses modal analysis and integral relationships to connect appropriate components of the field. In this way, convergence is achieved faster than by point-matching techniques. Our method is well adapted to resonance problems, as illustrated by comparison with both theoretical and experimental results     

波导金属插片窄带滤波器的研制

采用高精度的模式匹配法设计了一种窄带矩形波导插片滤波器。利用该方法设计的波导型滤波器精度高,结构简单,便于加工。同时将模式匹配法的数值计算结果与实验结果进行了比较,两者吻合的很好。     

An array of coupled nonradiative dielectric waveguide radiators

A novel antenna array that radiates a single mode of multiple coupled nonradiative dielectric (NRD) waveguides, is described. The array is fed by a single NRD waveguide, which is designed to propagate a wave with the same wave number as that of free-space. The individual radiators of the array are spaced at one free-space wavelength, but due to the narrow beamwidth of the individual radiators, grating lobes are effectively suppressed. An eight-element array is described and measurements presented, but the design method can be extended to any number of elements     

The problem of scattering by a curvilinear two-dimensionally inhomogeneous metal/dielectric cylinder in a rectangular waveguide

The problem of H-wave scattering by a metal/dielectric cylinder that is inhomogeneous over its curvilinear cross section and positioned perpendicularly to the wide wall is solved. According to the proposed method of solution, a system of external currents is associated with the cylinder with allowance for the selfmatching conditions.     

Scattering by an E plane dielectric sheet in rectangular waveguide

A method for the computation of S-parameters associated with a rectangular waveguide with a rectangular dielectric obstacle is presented. The method uses the Method of Lines and discretization of the dielectric permittivity to treat the dielectric discontinuity along the discretization direction. In this way, the Method of Lines can be applied to analyze waveguide discontinuity with dielectric inhomogenousity along the discretization direction. The numerical results have been verified by both theoretical and experimental results.     

The discontinuity problem of a rectangular dielectric post in arectangular waveguide

A simple numerical technique for the solution of the discontinuity problem of a symmetric loaded rectangular dielectric post centered in a rectangular waveguide is presented. The waveguide is divided into three regions where the field is expressed in suitable waveguide modes. By applying the continuity condition at the common surfaces of the regions, a system of linear equations determining the reflection and transmission coefficients is formed. Several examples are compared with experimental results and show the validity of the method     

Aperture coupled microstrip patch antenna fed by nonradiating dielectric waveguide

Owing to its low loss property at millimetre-wave frequencies, the nonradiating dielectric (NRD) waveguide is very attractive for use as a feed network in planar arrays. The design, fabrication and testing of a microstrip patch antenna fed by NRD guide at X-band is described. Radiation patterns are measured and presented.<>     

VARIATIONAL METHOD TO ANALYZE THE EQUIVALENT NETWORK OF A RECTANGULAR DIELECTRIC POST IN A RECTANGULAR WAVEGUIDE

The equivalent filter modeling of a rectangular dielectric post in a rectangular waveguide is obtained through the variational expression of input impedance. The reflection coefficient expressed in components of network is in good agreement with the results given by K. Siakavara, et al. (1991), The method can be applied to design filter.     

Nonradiative dielectric waveguide with perforated dielectric strip

The properties of a nonradiative dielectric waveguide with a dielectric strip perforated by a series of holes are described. The perforated guide can be used in instances where different wave impedances are desired, in addition to where different propagation velocities are needed without resorting to the use of physically different materials.     

An analysis of wave phenomena in a dielectric waveguide with periodic metal strips

An analysis of a dielectric waveguide periodically loaded with metal strips is presented. Numerical results are obtained from the formulation based on Galerkin's procedure in a space-harmonic domain. Experimental studies are conducted to correlate with theoretical results and to study the effect of finite length of the grating.     

矩形波导结中多介质柱散射特性边界元法分析

应用边界元法数值分析了n个端口矩形波导结中加载多介质柱的散射特性,对介质柱所在区域和除去介质柱后的空气区域分别用单连域和多连域问题的边界元法进行了分析。为了验证此方法的正确性,编制了一个通用的计算机程序,对几个算例进行了计算,结果与文献值一致。