曲折双脊槽波导高功率宽频带太赫兹行波管

提出一种改进的曲折槽波导—曲折双脊槽波导提高太赫兹行波管的功率和带宽.针对这种新型慢波结构设计了一种新的传输波导作为输入输出能量耦合器.从高频特性仿真结果可以发现曲折双脊槽波导可以提高耦合阻抗并扩展带宽.此外, 粒子仿真结果表明当电子注加载27.4kV电压和0.25A电流时, 新型曲折双脊槽波导行波管在中心频率340GHz处输出功率能达到65.8W同时对应增益27.21dB.因此, 曲折双脊槽波导行波管可以用作宽带和高功率太赫兹辐射源.     

曲折双脊槽波导高功率宽频带太赫兹行波管（英文）

提出一种改进的曲折槽波导—曲折双脊槽波导提高太赫兹行波管的功率和带宽.针对这种新型慢波结构设计了一种新的传输波导作为输入输出能量耦合器.从高频特性仿真结果可以发现曲折双脊槽波导可以提高耦合阻抗并扩展带宽.此外,粒子仿真结果表明当电子注加载27.4kV电压和0.25A电流时,新型曲折双脊槽波导行波管在中心频率340GHz处输出功率能达到65.8W同时对应增益27.21dB.因此,曲折双脊槽波导行波管可以用作宽带和高功率太赫兹辐射源.     

新型圆形槽波导定向耦合器

圆形槽波导是一种新型的高功率毫米波、亚毫米波传输线.为了实现圆形槽波导之间的耦合,本文根据双槽波导的耦合机理,设计出了新型圆形槽波导走向耦合器,并计算了3dB圆形槽波导定向耦合器的频率特性.     

非对称十字孔双脊波导定向耦合器的设计

借鉴波导定向耦合器的设计原理,采用双脊波导的形式（本文采用标准双脊波导WRD650型号）设计大功率宽频带定向耦合器。由于双脊波导相比于矩形波导,最低模式的截止频率更低,单模工作的频带更宽,特性阻抗更低,所以采用双脊波导的形式比矩形波导在带宽方面更有优势。波导耦合器耦合方式有很多种,最常用的有小孔耦合和缝隙耦合,本文采用非对称十字孔耦合的方式,并与等孔径分布和切比雪夫分布的圆孔耦合比较来确定非对称十字孔耦合方式,在耦合平坦度、方向性方面有更好的改进。利用电磁仿真软件进行仿真对比其结果,通过一些具体措施改善双脊波导定向耦合器的性能,使定向耦合器的各种设计指标达到要求。     

主副波导不同口径定向耦合器

叙述了不同口径主副波导的双十字槽定向耦合器的设计方法，给出了实验结果。文中经验公式是由成熟公式推导出的。耦合器的设计方法与实验结果相吻合     

0.5THz波导双定向耦合器设计

介绍了0.5 THz波导双定向耦合器的原理分析及仿真设计.采用双排多孔等间距不等孔径的方案,设计了0.325～0.5 THz宽带波导双定向耦合器,并给出了仿真及测试曲线.测试结果显示,0.5 THz波导双定向耦合器在0.325～0.5 THz全波导带宽内耦合度为(7.6±1)dB,方向性大于18 dB,输入端口回波损耗...     

部分介质填充槽波导色散特性的网络分析

本文给出了部分介质填充单槽和非对称双槽波导的横向等效网络。以此为基础,用微波网络方法分析了各种槽波导的色散特性,并将所得到的数据与用其它方法得到的结果进行比较,两者吻合好。证实本方法在保持有高的计算精度的情况下极大地简化了分析和求解过程。文中通过对宽带槽波导定向耦合器的具体设计,证明了本方法在槽波导电路分析和设计中的重要实际意义。     

硅基波导光栅耦合器与波导传输损耗的研究

对硅(Si)基波导光栅耦合器的设计与耦合性能进 行了研究。采用本征模展开法对光栅耦合器进行设计与 优化,通过实验测量了光栅的耦合性能,并对均匀光栅、自聚焦光栅和反射光栅等3种光栅 耦合器的耦合 性能进行了比较,耦合效率分别达到了达到47.86、56. 36和48.98%,自聚焦光栅可以有效改善光纤到 光纤的传输效果,耦合效率提高了8.5%。通过实验测量了基于耦合光 栅技术的Si基条形波导和槽型波导的 传输损耗,结果显示,条形波导和槽型波导的传输损耗分别为2.34d B/cm和6.31dB/mm。     

基片集成波导正弦渐变槽单脉冲天线

为拓展工作带宽,以传统正反渐变槽天线为基础,利用基片集成波导馈电,该文提出了两种高增益、宽频带的正弦渐变槽天线。利用矩形波导3 dB定向耦合器和90移相器工作原理设计了半模基片集成波导单脉冲馈电网络,进而得到了对称型和非对称型正弦渐变槽单脉冲天线,带宽均超过了3.0 GHz,带内和波束最大增益在9.0 dBi左右,差波束零深在10.0 GHz处均低于-20 dB。其中,非对称型正弦渐变槽单脉冲天线具有更宽的工作频带和更平稳的天线增益,可以广泛应用于微波定向探测系统中。     

一种新型半模基片集成波导三孔定向耦合器

半模基片集成波导(HMSIW)是近年来出现的一种高性能平面导波结构,具有传输损耗小、功率容量大、易于集成等优点,已开始广泛应用于微波无源器件的设计中。文章基于HMSIW技术与PCB工艺技术设计制作了一种新颖的三孔定向耦合器,通过在耦合孔上金属面蚀刻"工"字形槽增加孔的耦合量。设计的HMSIW三孔定向耦合器不仅保持了集成基片波导(SIW)定向耦合器的所有优点,而且在面积上减小了近50﹪,工作带宽拓展到1GHz。实测数据与仿真结果基本吻合,验证了设计方法的正确性与可行性。     

非对称GNRD波导耦合特性的计算

本文将两种尺寸不同的波导相互耦合可实现宽带耦合器的原理用于GNRD波导定向耦合器的设计。根据对非对称GNRD波导耦合特性的理论分析,定性讨论了各种非对称情况对耦合特性的影响;并设计了3dB GNRD波导非对称定向耦合器。计算结果表明其在8mm波段,耦合频带比原对称时的明显平坦。     

Optimum field theory design of broad-band E-plane branchguide phase shifters and 180° couplers

Optimum rectangular waveguide E-plane branch guide phase shifters and 180° branch guide couplers are designed with the rigorous method of field expansion into normalized eigenmodes. The design includes both the higher order mode interaction between the step discontinuities and the finite step and branch heights. The phase shifter design applies the Schiffman principle to branch guide couplers where two ports are short-circuited. The 180° coupler design combines the advantage of the broadband potential of multiple-branch couplers with the low-insertion-loss qualities of E-plane stub-loaded phase shifters. A computer-optimized phase shifter prototype for the waveguide Ku-band (12-18 GHz) shows a 90°±1° differential phase shift with reference to an empty waveguide within about 23% bandwidth. Five-branch three-stub coupler prototypes, designed for 3±0.2 dB coupling, for the waveguide Ku- and Ka-bands (26-40 GHz) achieve a 180°±1° differential phase shift at the output ports within about 19% bandwidth, as well as more than 30 dB isolation and return loss. The theory is verified by measured results     

Design and fabrication of broad-band silica-based optical waveguidecouplers with asymmetric structure

Waveguide-type directional couplers with different guide widths in the interactive region are designed and fabricated with silica-based waveguides on silicon substrates. It is demonstrated that these asymmetric couplers have broadband coupling-ratios of, for example, 50%±5%, 25%±3%, or 5%±2% over a wide wavelength range from 1.3 to 1.55 μm, which are in good agreement with the results calculated using the beam propagation method (BPM). The excess loss of these couplers is as low as 0.7 dB, including input and output single-mode fiber coupling losses     

LEAKY CHARACTERISTICS OF A NEW MILLIMETER WAVE ANTENNA BASED ON GROOVE GUIDE WITH AN ASYMMETRIC CONDUCTOR STRIP

A new millimeter wave leaky wave antenna is presented in this paper, which is a modification of the groove guide with an asymmetric conductor strip by introducing a dielectric slab into the conductor plane region of the groove guide antenna. The leakage property of the new antenna is carefully examined through calculations of an equivalent network, which is developed here with taking into account the coupling between different modes to guarantee the calculating accuracy. It has been found that the new leaky wave antenna is of larger leakage constant than that for the original groove guide antenna because of the introduction of the dielectric slab. Extensive numerical results of the leakage characteristics are given to establish useful guidelines for the design of the new type groove guide leaky wave antenna.     

Non-radiative phenomenon in couple dielectric guide

The solutions of electromagnetic field equations for non-radiative coupled dielectric guides are derived using mode matching technique. Dispersion curves are plotted for various dielectric materials and dimensional parameters. The non-radiative phenomenon in the coupled dielectric guide has been discussed in detail. The hybrid directional couplers in the above configuration have been theoretically designed by computing the normalized propagation constants. The superiority of such directional couplers is discussed.     

Transmission characteristics of several kinds of closed groove waveguides for millimeter waves

An advantage of closed groove guide over open groove guide is attended. In this paper, the several kinds of closed groove guides including the trapezoidal-, elliptic- and parabolic-groove guides as new types of millimeter wave transmission lines are presented. Their dispersion and cut-off characteristics of the dominant mode are analysed and compared with ones of the closed V-and circular- groove guides by using the equivalent network method. The obtained results have important meaning in theoretical studies and actual applications of groove waveguides.     

Analysis for a Novel Cocoon-Shaped Groove Guide with Method of Lines

An arbitrarily cross-sectional groove guide is analyzed by using the method of lines and its characteristic equations are gives for TE and TM modes. Some numerical results show that correctness of the method of lines compared with the relevant results in the references is verified, and it is convenient to solve groove guide with arbitrary shape in practical application problems. A novel cocoon-shaped groove guide is firstly presented and its transmission characteristics are analyzed and discussed. The new type of cocoon-shaped groove guide has the good performances. The obtained results are of important application values in theoretical studies and practical applications of groove guides for millimeter waves.     

Three-guide optical couplers in GaAs

Three-guide optical couplers consisting of three 4.75-μm-wide slab-coupled rib guides separated by 4.25μm have been fabricated in GaAs. The performance of these couplers at 1.28 μm is in close agreement with that predicted using a modified effective-index method to obtain an approximate analytical solution for this type of coupler. The coupling length needed to symmetrically transfer power from the center guide to the two outside guides was 3.2 mm. At this length, less than 1 percent of the power remained in the center guide. The length needed to transfer power from one outside guide to the other outside guide was ≈ 6.4 mm, which isapprox sqrt{2}- times that of a similar two-guide coupler and twice that required to couple power from the center guide to the two outside guides. The power transfer efficiency in this case is not as good as when power was inputted into the center guide. Three-guide couplers of this type should prove useful as power dividers and combiners, especially in cases where waveguide bend losses preclude the use of"Y"- junctions. They may also prove useful as replacements for two-guide couplers where either sharper transfer characteristics are desired or where losses due to waveguide bends are again unacceptable.