一种使用TE11为过渡模的TE01-HE11模式变换器设计

基于弯曲圆波导耦合理论和规则圆波导突变结构模式匹配法, 利用MATLAB软件编写的相关数值计算程序得到波导模式转换结构的优化参量, 最终使用CST软件对模型进行了仿真和验证.该系统主要由三部分组成: 一个TE01-TE01的过渡器, TE01-TE11和TE11-HE11的圆波导模式转换器.计算结果表明, 该TE01-HE11模式转换系统在24.13 GHz的频率有5%的带宽、转换效率超过了99%.计算结果、仿真结果和实物冷测结果是一致的.     

TE01-TE11 mode transducer

A transition between rectangular waveguide and circular groove guide is described. The composite transition consists of two sections. It is theoretically designed to provide both mode matching as well as low reflection coefficient. The performance of the transducer is plotted.     

TE03 to TE01 mode converters for use with a 150 GHz gyrotron

Two-step high-power TE03-to-TE01 mode transducers (TE02 is the intermediate mode) were designed to transform the TE03 output mode of the 150 GHz KfK gyrotron into the fundamental circular symmetric TE01 mode for low-loss propagation and further conversion into the linearly polarized quasioptical HE11 mode. The advanced perturbation structures of the ruppled-wall mode converters (with input- and output-diameter D=27.8 mm) were optimized by numerically solving the proper coupled-wave differential equations. The overall TE03-to-TE01 conversion efficiency at 150 GHz was calculated to be η₀=99.1% for a long converter (total length L=2.67 m) and η₀=97.8% for a short converter (L=1.07 m); ohmic attenuation is included. The corresponding theoretical bandwidth (for η≧95%) is ±1.4 GHz and ±2 GHz, respectively. Low-power experimental data are in excellent agreement with these computed values.     

50mm diameter TE01 mode helical waveguide optimisation

Changes to the design of the UK Post Office long distance TE01 mode circular waveguide are described. A 250 m length of the new waveguide structure has been manufactured and assessed; its transmission performance in straight route sections has been improved and much lower loss in curved sections has been achieved.     

TE On o -to- mode transducer designmode transducer design

This paper gives a structure on the mode converter from TE _0n ^O mode of gyrotron output to the main mode of the circular groove guide. The design consists of two parts: the first part is to convert TE _0n ^O to TE ₀₁ ^O using an advanced periodic wall perturbation technology, the second part is to convert TE ₀₁ ^O to mode basing on the method of gradually changing the wave guide cross section. An example at 37.5Ghz is given. For the first part, the efficiency is 94.71%, the length is 1.868m. For the second part, the theoretic figure of reflectance coefficient vs. frequency is given.     

94GHzTE6,2模内置准光模式变换器

提出了可应用于94 GHz回旋管内部的TE6,2准光模式变换器.根据几何光学和矢量绕射理论编制了模拟其电磁行为的分析和优化程序.根据几何光学原理,设计了该模式变换器的初步结构参数,然后利用该优化程序获得了最优化的相关参数.优化结果表明,在94 GHz,该准光变换器功率转换效率约为85%,转换所得波束高斯含量高于70%.     

TE/TM mode splitters on InGaAsP/InP

In a monolithic heterodyne polarization diversity receiver, mode splitters which effectively separate the TE and TM polarization of the optical wave are required. For this purpose, a directional coupler which utilizes a metal cladding on one of its branches to separate both polarizations was investigated. The polarization splitters can act in two distinct modes of operation, depending on the degree of lateral confinement of the optical rib waveguide before an asymmetric coupler. For weak confinement, the metallized waveguide is guiding for TE- but nonguiding for TM-polarization, and negligible TM-crosstalk results     

High power millimeter-wave TE03 to TM11 mode converters

Transmission of power from 42 ± 0.2 GHz gyrotron (TE₀₃ mode) to tokamak or dummy load requires a set of transmission line components. It includes a set of mode converters that converts circularly unpolarised TE₀₃ mode to polarised HE₁₁ mode. The mode conversion sequence is methodised in two steps; first from TE₀₃ to TE₀₁ mode and then from TE₀₁ to TM₁₁ mode. The proposed mode converters performance depends on the parameters such as waveguide radius, beat wavelength, number of ripples, its perturbation amplitude (η) and bending angle. These parameters are numerically optimised and verified in CST microwave studio. TE₀₃ to TE₀₁ mode conversion is realised by the generation of intermediate mode TE₀₂. The mode conversion length for TE₀₃ to TE₀₂ mode converter is6λ₀, (where λ_b is the beat wavelength of corresponding mode conversion) which converts 99.15% of an incident circular TE₀₃ mode power into TE₀₂ mode power. Next, mode converter converts TE₀₂ mode into TE₀₁ mode with 99.06% efficiency along the optimal length of6λ_b. For TE₀₁ to TM₁₁ mode conversion, two conversion methodologies have been proposed: first using axis arc bend (34.94°) technique to convert TE₀₁ into its analogous degenerate mode with 99.01% conversion efficiency and second using parabolic curve with 90° bend, which gives a conversion efficiency of 97.5%.     

Asymptotic behaviour of TE11 mode coupling in circular apertures

An asymptotic formula for mode coupling in a finite planar array of circular apertures, which was derived previously, is compared with the exact solution for the case of TE11 mode coupling in two circular waveguides. It is shown that for dominant mode operation of a circular waveguide the asymptotic formula is accurate enough for most practical purposes, even for aperture spacings of the order of a wavelength.     

Q波段圆波导轴线弯曲TE01-TE11模式变换器设计

在模式耦合理论的基础上, 采用相位重匹配技术对圆波导轴线弯曲TE01-TE11模式变换器进行了数值优化计算和分析.在Q波段给出了两种不同周期数TE01-TE11模式变换器的优化设计参数.数值计算表明: 四周期模式变换器的最高转换效率为98.82%, 带宽为2.2 GHz, 六周期最高转换效率为99.89%, 带宽为1.7 GHz.研究了模式变换器关键几何尺寸在小范围内变化对转换效率的影响.并利用HFSS对给出的模式变换器进行了仿真, 仿真结果与数值模拟一致性较好.同时加工了六周期结构模式变换器并进行了小功率热测实验, 测试结果表明输出了模式纯度较高的TE11模式.     

Novel structure for TE°11-TE11 mode converter

A novel structure for the transition from the dominant mode in circular waveguide to that in circular groove guide is presented. The mode converter based on this structure which has low reflection coefficient is designed. The numerical result shows that the performance of this new type of transducer is improved.     

A phase-plate mode transducer for TE1n gyrotron modes

A means is described to increase the on-axis component of the far-field energy pattern of radiation emitted from the open end of a circular waveguide containing a high order TE_1n gyrotron mode. While the sidelobe power is higher than that of some other approaches, this technique is relatively broadband and compact, and should be easy to fabricate. The method uses a phase-plate at the output of the waveguide to rectify the negative portion(s) of the electric field of the circular TE mode in the waveguide.     

94GHzTE5,3准光辐射器

基于耦合波理论和相位匹配技术,对准光辐射器的传统设计方法进行了改进,使其适用于低阶模式的设计.通过调节耦合时模式间的相位,在切口处实现了具有高斯场分布的理想模式组合.利用这一方法,优化设计了一个94 GHz,TE5,3回旋管准光辐射器.数值模拟结果表明,设计的辐射器在切口处形成了一个良好的束斑,边馈电平达到-30 dB,口径场高斯含量高于98%.     

新型C频段TE21模圆极化合成网络设计

指出了波导结构及微带形式的TE21模圆极化合成网络的不足,介绍了3 dB分支定向耦舍器的基本原理,设计了新型C频段空气带状线形式的圆极化合成网络,并对该结构进行仿真和测试,结果满足性能要求.此种合成网络可与耦合器设计为一体,既可以增加结构强度,还缩短了传输路径,降低了损耗,目前已经成功应用在多种型号天线系统上.     

An integrated optic adiabatic TE/TM mode splitter on silicon

A compact integrated optic fundamental TE/TM mode splitter, based on the mode-sorting characteristics of an asymmetrical adiabatic Y junction of optical waveguides exhibiting shape birefringence, operating at 1550 nm, is designed, using the discrete sine method (DSM) and the beam propagation method (BPM). The structures are fabricated in a system of SiO₂, SiO_xN_y, and Si₃N ₄ layers, using a low-temperature plasma-enhanced chemical-vapor deposition (PECVD) process, compatible with standard silicon IC processing     

空心平板光波导中二脉冲TE模的光子回波

讨论了空心平板光波导中二脉冲TE模光子回波问题(包括单阶模和多阶模两种情况),所得结果表明,空心平板光波导中的光子回波与非波导情况下的相比,具有许多不同的性质.     

Design of mode converters for generating the TE11 mode from TM01 vircator at 4GHz

This work reports on measurements and calculations (coupled mode equations) on the conversion of transverse magnetic TM₀₁ vircator mode at 4 GHz to the linearly polarized TE₁₁ mode by means of mode converter systems using a circular waveguide with curvature. The mode converter is composed of a 38.78° bend with 39.07 cm curvature and a 50.78° inverse bend with 25.24 cm curvature in 9 cm internal diameter (ID) circular waveguide. The efficiency of conversion from TM₀₁ to TE₁₁ at 4 GHz exceeds 99%, and the overall efficiency from TM₀₁ to TE₁₁ exceeds 90% over a calculated range of 3.72–4.8 GHz.     

Vectorial simulation of passive TE/TM mode converter devices on InP

Accurate calculations of polarization rotation at abrupt waveguide interfaces are performed by a vectorial two-dimensional finite difference scheme. It is shown that the small orthogonal component of the vector field in rib waveguides can play an important role in mode polarization rotation. Polarization rotations in mode converters fabricated on InGaAsP/InP by periodically arranged tilted waveguides or periodic loading of the rib are explained by these calculations, and design rules for passive mode converter devices are given