Longitudinal Wave Propagation in Dielectric Waveguide Array

Based on the established rigorous theory for two-dimensionally periodic (2DP) medium, Longitudinal propagation in Dielectric Waveguide Array (DWA) was analyzed in detail. Firstly, given longitudinal wave vector (k _z), Brillouin dispersion relations between transversal wave vectors were analyzed. Interactions between space harmonics were also studied. Secondly, on condition that transversal wave vector k _x equaled k _y, dispersion relations between longitudinal and transversal wave vectors were analyzed in detail. Because of interactions between space harmonics increasingly getting stronger with k _z or modulation coefficients increasing, stop-bands could be distinctly displayed and thus longitudinal propagation in DWA could be comprehensively analyzed. The applications about longitudinal propagation in DWA were also discussed.     

The Amplitude of Longitudinal Characteristic Modes in Dielectric Waveguide Array

It's not adequate to just obtain eigenvalue for solving eigenvalue problem. Since the eigenvalues associated with longitudinal characteristic modes in dielectric waveguide array (DWA) has been studied, the paper concentrates on the corresponding eigenvector, namely, the amplitude of these characteristic modes. Through numerical study of the amplitude of longitudinal guided TE and TM modes in DWA, space harmonic (SH) coupling and energy conversion effect have been discovered. The paper not only contribute to deep understand the mechanism of SH interaction, but also do good to analyze the resonance, radiation problem in DWA.     

Transverse Propagation in Dielectric Waveguide Array

Transverse propagation eigen equations for dielectric waveguide array (DWA) are derived and eigen solutions can be uncoupled into TE and TM modes. Numerical results shows that much stronger space harmonic interaction exists so that a series of interesting physical effect of canonical two-dimensionally periodic (2DP) medium can obviously be observed in DWA and related devices can be predicted, designed and realized much easier.     

Characteristic Electromagnetic Fields in Dielectric Waveguide Array

Based on the modal solution of one dimensionally periodic structure with piecewise uniform dielectric constant distribution, characteristic solutions for two dimensionally Dielectric Waveguide Array (DWA) are rigorously formulated. By satisfying periodic boundary conditions in the interfaces inside a unit cell, semi-closed-form dispersion relation for DWA can be established. Numerical results are presented and compared with a previous method. A class of guidance and radiation problems can be solved with much more simplicity and accuracy.     

介质波导阵列的横向传播特性分析

根据已提出的有关二维周期介质严格分析理论，针对介质波导阵列进行了大量的数值计算。对介质波导阵列中波的横向传播作了详细分析。首先，在给定纵向波矢量(k)的情况下，分析了在不同工作频率时的横向波矢量间布里渊区色散特性，对空间谐波的相互作用情况也进行了研究。其次，在给定工作频率的情况下，分析了不同纵向波矢量和不同调制系数时的横向波矢量间布里渊区色散特性。由于空间谐波的相互作用随纵向波数或调制系数的增大而增强，导致阻带能明显地表现出来，从而使介质波导阵列的横向传播特性能较为全面地得到分析。     

矩形介质波导阵列的一种新型分析方法

本文将等效介电常数近似分析方法在应用范围和处理方法上进行了一些改进．发展为双等效介电常数近似分析法，然后用它来分析矩形介质波导阵列．推得两个一维周期的耦合特征方程。如果将Macatili方法应用范围扩展用来研究该波导阵列也会得到同样的结果，它们都能在二维平面上较准确地反应出通带和阻带等主要周期特性。     

Rigorous Analysis of Electromagnetic Wave Propagation in Cylindrical Dielectric Waveguide Array

Cylindrical Dielectric Waveguide Array(CDWA) should be considered as a kind of two-dimensionally periodic(2DP) medium. Based on the established rigorous theory for 2DP medium, a great amount of numerical results for CDWA were presented. Wave propagation in CDWA was analyzed in detail in this paper. Firstly, given the longitudinal wave vector (k _z=0), Brillouin dispersion relations between transverse wave vectors were analyzed when modulation coefficients or the rate of different dielectric areas in a unit cell varied. Interactions between space harmonics were also studied. Secondly, when the area of dielectric cylinder in the unit cell varied within a given range, CDWA dispersion relations were compared with Rectangle Dielectric Waveguide Array's, some interesting conclusions were obtained.     

The Convergence of the Eigen Equation for Dielectric Waveguide Array

The eigen equation for Dielectric Waveguide Array (DWA) established by [1] was discussed. The convergence of the eigen equation was also analyzed in detail. Numerical results for a particular rectangular DWA was presented. Compared with those obtained by previous different ways, faster convergence for the eigen equation was reached easily. The characteristics of the eigen equation for DWA was particularly useful in computer propramming and engineering.     

Ka-band Dielectric Waveguide Antenna Array for Millimeter Wave Active Imaging System

Ka-band compact dielectric waveguide antenna array for active imaging system is given. Antenna array with WR28 metal waveguide direct feeding is specially designed with small size, high gain, good radiation pattern, easy realization, low insertion loss and low mutual coupling. One practical antenna array for 3-D active imaging system is shown with theoretic analysis and experimental results. The mutual coupling of transmitting and receiving units is less than -30dB, the gain from 26.5GHz to 40GHz is (12-16) dB. The results in this paper provide guidelines for the designing of millimeter wave dielectric waveguide antenna array.     

Ka波段大型单脉冲平板缝隙天线的分析与设计

论文所分析的Ka波段平板缝隙阵列天线具有阵面尺寸大(534.89mm×494.3mm)、缝隙多(5 120)的特点,因而对于阵面的设计运用优化总体设计,并运用等效电路法结合电磁仿真软件HFSS得到精确的辐射缝以及耦合缝参数。同时为了减小加工难度,对天线分象限分层分象限进行加工。经过实测验证,测试结果与理论吻合良好,在±300MHz频带范围内驻波小于2,整个阵面的增益均大于42dB,天线的方位副瓣电平达到-22.8dB,俯仰副瓣电平达到-23.8dB,零值深度在俯仰和方位均达到-30dB。     

Dielectric Waveguide Theory

We attempt a brief and broad overview and historical perspective of the theory of lightwave propagation in dielectric waveguides. This is a subject that is now documented by extensive literature. As our review task is limited by constraints in both space and time it will be illustrative rather than comprehensive. The illustrations are intended to highlight the principal concepts and theoretical approaches and refer the reader to the literature for detailed derivations and explanations. Our story celebrates a theory with a proud history of nearly 100 years, vibrant and rich in new ideas, and serving as the base for an increasing number of powerful applications.     

Practical Dielectric Filled Waveguide

This paper describes the development of a laminated teflon-filled dielectric waveguide using techniques similar to what has been done in the flexible coaxial line. It describes the development of dielectric waveguide giving the theoretical design of the teflon-filled dielectric waveguide from both a mechanical and electrical point of view.     

Wide-Band Directional Couplers in Dielectric Waveguide

In this work, the H guide is proposed as an alternative in designing proximity directional couplers using dielectric guides in order to obtain coupling factors constant with the frequency, thus increasing the bandwidth of these devices. The propagation constants of the even and odd modes of the coupling zones are determined by means of Schelkunoff's method and the effective dielectric constant method (EDCM). Two directional couplers, 10 dB and 3 dB, made of polystyrene and Teflon respectively, were designed and measured to work in the millimetric frequency band (32-40 GHz). The inclusion of metallic walls in the curved zones avoids additional couplings and results in flat coupling. Furthermore, the metallic walls reduce the radiation losses and allow the coupling factor to be finely adjusted. The results obtained show a maximum coupling variation of +-0.5 dB for 20-percent bandwidth.     

半导体光波导开关列阵

光波导开关是光网络的基础器件。半导体中的电光效应、能带填充效应、多量子阱的量子限制Stark效应以及等离子体色散效应等都可分别被利用来制作成光波导开关。本文综合介绍基于上述效应的光波导开关的发展动态。     

Multiple Dielectric Posts in a Rectangular Waveguide

This paper presents a complete analysis for a system of Iinear, homogeneous, and isotropic dielectric posts in a rectangular waveguide. These posts are assumed uniform along the narrow side of the waveguide, but are otherwise of arbitrary cross section and thickness. The scattering and impedance matrices describing the effect of the posts on the dominant waveguide mode are derived. The latter is then realized as a two-port T-network. A moment procedure is devised and applied to a set of test problems with a wide variety of post configurations to compute the scattering parameters and equivalent network elements. The accuracy and convergence aspects of the numerical solution are also investigated. The branch and network resonances are determined for some post configurations.     

Propagation in Dielectric Slab Loaded Rectangular Waveguide

Propagation in dielectric loaded rectangular waveguide is investigated theoretically for varying slab thickness and dielectric constant. The slabs are placed across the center of the waveguide in the E plane. This geometry is found to offer bandwidths in excess of double that of rectangular waveguide for dielectrics having dielectric constants of approximately 18. Power handling capacities which are double or triple that of standard waveguide are achievable using the dielectric loaded waveguide. In addition to the theory, design curves of bandwidth, guide wavelength, cutoff wavelength, impedance, power handling capacity, wall losses, and dielectric losses are presented and compared to experiment where possible.     

Dielectric Resonator in a Waveguide Below Cutoff

A structure is considered consisting of a waveguide 2 below cutoff, connected to waveguides above cutoff, 1 and 3, by means of suitable junctions. A dielectric resonator is introduced in waveguide 2. Its effect on the transmission curve of the structure is evaluated in the limit epsilon/sub r/spl rarr/spl infin/. Theoretical results are compared with experiment.     

Distributed Bragg Reflection Dielectric Waveguide Oscillators

Dielectric waveguide Gunn oscillators are presented in which the cavity consists of grating structures exhibiting either the surface-wave stopband or the leaky-wave stopband. Oscillation conditions and design criteria of the grating structures are studied. When a grating exhibiting the leaky-wave stopband is used in the oscillator, the extraction of the output power in the direction perpendicular to the dielectric waveguide axis is possible. This is because such a grating becomes a broadside-firing leaky-wave antenna with high input VSWR.     

沟槽型无辐射介质波导的耦合特性

本文采用横向谐振法和奇、偶激励法分析了平行耦合和对称弯曲耦合的沟槽型无辐射介质(GNRD)波导的耦合特性,并对实验样品进行了测试。理论计算结果和实验结果符合良好,为GNRD波导定向耦合器等元件的设计提供了理论依据。