矩形波导到圆波导模式变换器的优化设计

在圆形槽波导微波毫米波器件中,常遇到矩形一圆形槽波导的模式变换问题,而矩形一圆波导模式变换是矩形一圆形槽波导模式变换的重要组成部分。本文应用有限元方法,首先由分析N端口波导结问题过渡到两端口的矩形一圆波导模式变换器,然后针对现有模式变换器的圆端口面的电场极化方向倾斜的问题利用加圆波导段的方法进行了优化,并设计了一个新的反射微小,结构紧凑和电场极化方向竖直的矩形一圆波导模式变换器．计算结果满足了设计要求。     

Optical coupling between single-mode semiconductor lasers and strip waveguides

This analysis describes the optimum conditions for coupling a single-mode semiconductor laser to a single-mode strip waveguide, when both the laser and the waveguide have asymmetric optical beam profiles. The outputs are approximated by two Gaussian fields. Two waveguide cases are treated: 1) the case where the two orthogonal waveguide waists are independent and 2) where the ratio of these waists is fixed. The effect on the coupling efficiency of a spherical surface on the waveguide input face is discussed. The results demonstrate the importance of coupling in the laser far-field and indicate the advantage of having relatively large waveguide modes. An intrinsic minimum in the optimum coupling efficiency was found to exist in the near-field for asymmetric laser/waveguide systems. Expressions describing the optimum waveguide waists and the focal length of the lensed waveguide are given for the waveguide parameters that yield the best coupling conditions.     

Machined waveguide twist

A solution to the problem of obtaining a 90° twist in a machined-aluminium block waveguide is presented. At the waveguide input, half the waveguide wide-dimension is machined into one aluminum block the mirror image being machined into a second block. The technique involves gradually reducing the width of the input waveguide in one block, and simultaneously increasing the depth of the waveguide in the opposite block until the output waveguide depth is equal to the input waveguide width. Care must be taken to maintain a constant waveguide cutoff frequency through the length of the twisted section so that a good match is obtained. Two twists made using this technique in WR-22 waveguide are shown to give satisfactory results     

螺旋波纹波导在高功率微波领域中的应用研究

螺旋波纹波导是一种具有特殊结构的高功率微波源波导结构,螺旋波纹波导的特殊结构使得TE11和TE21两模式在角向耦合,耦合出的新工作模式具有良好的色散特性和模式选择特性,因此该波导具有广泛的应用价值。简要地介绍了螺旋波纹波导的结构原理,概述了该波导在高功率微波领域的工作原理。通过分析和模拟计算表明,螺旋波纹波导在高功率微波源中极具发展潜力,值得进一步研究。     

A multipole analysis of a dielectric loaded coaxial rectangularwaveguide

A multipole analysis of a coaxial rectangular waveguide whose inner conductor is circular is made in order to determine the TE and TM modes of the system. The analysis is based on using multipole (dipole, quadrupole etc.) electric and magnetic current sources to generate field solutions in the waveguide. These solutions are used to match the electromagnetic boundary condition in a homogeneous coaxial rectangular waveguide and to determine the TE and TM eigenvalues of the waveguide system. Eigenvalue results are compared with results of the generalized spectral domain method and to eigenvalue results for a ridged waveguide. Propagation in a coaxial rectangular waveguide is also studied when the coaxial rectangular waveguide is loaded with lossy inhomogeneous dielectric material. A variational formula is used to relate the TEM, TE, and TM modes of an empty coaxial rectangular waveguide to the propagation in the loaded inhomogeneous dielectric waveguide     

太赫兹过模传输线损耗研究

太赫兹波的频率较高,在波导传输中损耗较大。本文采用微扰法对太赫兹波在矩形波导和圆波导中传输时的损耗进行了理论分析,并对矩形波导与圆波导中不同频率,不同尺寸以及不同模式的衰减特性进行了比较,结果表明采用圆波导TEo。模传输可获得最小的衰减。     

双面金属包覆单轴晶体波导的偏振转换研究

利用转移矩阵方法计算了双面金属包覆单轴晶体波导结构中的色散曲线、反射谱。结果表明,双面金属包覆结构使得波导可以被自由空间光场激发;单轴晶体的光轴取向能对该结构中的波导模式进行调控,使入射光波中的Ey、Ez分量发生相互转换耦合,从而在波导层中形成杂化模。通过调节耦合金属层厚度可以对出射光偏振状态的控制,实现TE线偏振入射光向TM线偏振反射光的转换以及线偏振入射光向圆偏振反射光的转换。     

一种销钉波导的分析方法

为了解决销钉波导端口阻抗参数计算复杂问题,采用一种新的分析方法,建立单销钉波导等效电路模型,利用级联规律,在分析三销钉波导时,把3个单销钉的等效电路级联起来进行分析,从电路角度解决销钉波导问题。把通过HFSS电磁仿真软件计算的销钉波导端口的阻抗参数与通过等效电路计算的销钉波导端口阻抗参数进行对比,两者结果一致。验证了该销钉波导等效电路的正确性以及这种销钉波导的分析方法的有效性。     

Polymeric Waveguide Optical Switch With Bascule Structure Using Novel Trench Forming Process

We develop a polymeric waveguide optical switch with a bascule structure. Our novel matrix switch diverts light from one waveguide to a crossing waveguide in a polymeric waveguide film, using total internal reflection (TIR) of the interface between a waveguide and a trench at the waveguide cross point by mechanical actuation. The key technique for achieving a low-loss property is a novel cleaving method of forming trenches at waveguide cross points. We achieved a loss of 5 dB for the longest path of an 8 times 8 matrix switch demonstrator, high speed switching operation up to 100 mus, and reliable performance over 10 million times switching.     

脊波导各种参数的计算

给出脊波导的主要参数：主模截止波长、脊波导单模工作带宽、脊波导特性阻抗、脊波导功率容量、脊波导衰减，及各参数的完备计算方法、部分参数的修正曲线。     

跳变折叠波导的空间谐波选择性的研究

折叠波导是由传统的规则波导在平面内周期性弯曲而成的,它与其它的慢波系统相比有很多独特的优点.而变周期折叠波导是将折叠波导的周期由固定改为可变而形成的,它在保持了普通折叠波导的诸多优点的基础上,还具有谐波选择、带宽宽的优点.本文以三段周期跳变的折叠波导为研究对象,分析了其空间谐波的情况,并研究了其选择空间谐波的工作原理,最后得出了在该系统中实现谐波选择的条件.     

基于有限元方法的波导管结构电磁屏蔽屏蔽效能分析

提出一种在屏蔽箱体孔缝结构的外部增加截止波导管结构的方法,利用截止波导管对高频电磁波的衰减作用来提高屏蔽箱体屏蔽效能。基于有限元法分别对截止波导管的长度、厚度及其形状进行仿真,仿真结果表明:在0.1 GHz~1 GHz频率范围内,随着截止波导管长度及厚度的增加屏蔽箱体屏蔽效能提高15d B以上,圆形和矩形截止波导管对屏蔽效能影响不大。根据实际情况合理选择截止波导管的长度及厚度可以提高微弱信号处理电路的电磁抗干扰能力。     

Comparative analysis of the method-of-lines for three-dimensionalcurved dielectric waveguides

We discuss the effects of waveguide geometry on the radiation loss of tightly curved multimode dielectric waveguides. Three waveguide geometries are investigated: a ridge waveguide, a buried waveguide, and an interdiffused waveguide. We compare the effective index method with both semi- and full-vectorial method-of-lines analyses for these waveguide geometries. This comparison shows that the effective index method is accurate for curved waveguides except where the outer confinement region is in cut-off or, in the case of TM-polarization, for the ridge waveguide. In the latter case, the full-vectorial method-of-lines predicts a resonant feature of the TM-mode radiation loss of curved ridge waveguides; this is not predicted by either the semivectorial method-of-lines or the effective index method     

周期损耗介质加载波导与均匀圆波导间的模式映射

损耗介质环与金属环间隔加载的周期损耗介质波导能够有效地控制各种模式的衰减特性,这对于抑制毫米波回旋行波管放大器的绝对不稳定性和提高其性能具有重要作用.针对应用于Ka波段、TE01模的回旋行波管放大器的周期损耗介质加载圆波导,系统地分析了该周期系统与均匀系统间的模式映射关系.研究表明,当介质层厚度一定时,均匀介质加载波导中的高阶模式可以映射为光滑波导中的低阶模式,且相互映射的模式在中空区域的场型一致.周期系统中的模式表现出复合模式的分布.在一个周期中,介质段和金属段的模式分别映射为均匀介质波导和金属波导中的模式.明确周期介质加载波导系统与均匀波导系统间的模式映射关系是分析发生在这种复杂的互作用回路中的回旋电子脉塞注波互作用的前提,对简化其物理模型具有指导作用.     

控制殷钢波导变形的工艺方法

针对某型产品中殷钢波导组件的材料和加工特性进行分析,指出殷钢波导管拉制成型及加工产生的残余应力是导致波导管出现弯扭变形的主要原因,抑制变形和消除变形是殷钢波导制造加工中的工艺技术难题。对殷钢波导的材料、成形及结构工艺性作了必要的阐述,结合工艺试验对如何抑制殷钢波导加工中的变形提出解决方法,确定了优化的工艺方案。     

Rectangular and Ridge Waveguide

This paper describes the present state of the art with respect to rectangular ridge waveguide giving tables and data from standard waveguide sizes and constructional techniques for both rigid and flexible waveguide. The problems inherent in waveguide connectors are discussed along with the various methods for producing waveguide assemblies. The problems inherent with present-day waveguide standardization are also discussed. It is essential that a series of standard waveguide for high pressure operation and for extremely broadband operation (ridgeguide) be standardized. The latest RETMA miniature standard flanges are shown along with present-day thinking on a series of pressurized contact flanges.     

0.41 THz折叠波导慢波结构分析与设计

在0.14 THz,0.22 THz和0.34 THz折叠波导行波管研制的基础上,讨论了0.41 THz折叠波导行波管慢波结构设计与加工的可行性,分析研究了折叠波导慢波结构弯曲处直角弯曲与半圈弯曲、方形电子注通道与圆形电子注通道对色散特性、耦合阻抗、带宽、冷损耗和增益的影响。考虑了慢波结构中增加理想衰减器对该行波管带宽和增益的影响,得到了0.41 THz折叠波导行波管慢波结构的初步设计方案,为太赫兹折叠波导行波管的继续发展打下了一定基础。     

A Transition from Rectangular to Nonradiating Dielectric Waveguide (Short Paper)

A transition between standard X-band waveguide and non-radiating dielectric (NRD) waveguide is described. It consists of a transition from air-filled rectangular waveguide to reduced-width dielectric-filled waveguide, cascaded with a transition to NRD. Both transitions are theoretically designed to provide both mode matching as well as a low reflection coefficient. The composite transition can be used for measurements in NRD while making use of conventional waveguide test equipment.     

截止波导理论中的波型耦合问题

本文从理论上证明:当截止波导口上纵向磁场不为零时,磁波将导致波型耦合,这种耦合还将随着截止波导长度的改变而周期变化.从而解释了截止波导或截止波导滤波器存在有限工作频率范围的原因.为了消除或减弱截止波导的波型耦合,需要对截止波导进行特殊的设计.     

用有限差分光束传输法分析过渡波导损耗

为了减小弯曲过渡波导和斜坡过渡波导的功耗,设计研究了几种过渡波导形状函数,并用有限差分光束传输法进行了模拟分析,发现过渡波导形状的选取与坡度和曲折角存在一定的条件关系,经总结给出了该条件关系表达式;并且,在分析计算不同形状过渡波导损耗的过程中,凸现出了有限差分光束传播法在光波导器件及其单元器件模拟分析中的直观性与方便性。