小孔耦合型双通道太赫兹波导定向耦合器设计

提出了一种小孔耦合型双通道太赫兹波导定向耦合器,采用新颖的阶梯结构,将两个单通道耦合器结合,可在双通道内实现相同的耦合输出。研究结果表明,在180~260 GHz的频率范围内,该耦合器的耦合度为10 dB,输出最大误差小于1.6 dB,回波损耗大于25 dB,隔离度大于35 dB,相对带宽达到36%。与传统的太赫兹波导定向耦合器相比,该耦合器能够实现双通道的耦合输出,在太赫兹系统中可用于双通道的功率检测、功率合成与分配。     

宽频太赫兹非对称主副波导定向耦合器设计

基于微型无人机雷达、精确制导武器雷达及无线通信终端设备的应用前景,设计了一种非对称主副波导定向耦合器。该耦合器采用主副波导为不同形状的等间距多孔耦合结构,将主矩形波导TE10模的信号耦合到副圆形波导TE11模中,利用相位叠加原理使得隔离端口相位达到反向相消的效果,能够得到良好的耦合度和隔离度。该耦合器中心频率为400 GHz,相对带宽为40 GHz,结果表明,定向耦合器耦合度达到-13.8～-12.8 d B,实现了弱耦合效果且耦合度稳定性较好,隔离度优于-24.5dB,直通插入损耗为-3～-2.5 dB,性能良好。     

太赫兹E 面分支波导定向耦合器研究

本文基于微细加工技术中的深反应离子刻蚀（DRIE）技术设计了一款中心频率在0.355THz 的E 面3dB 四分支 矩形波导定向耦合器。利用奇偶模分析方法和级联理论分析方法进行分析,计算出了其在给定耦合度条件下各结构初值。 使用Ansoft HFSS 对四分支波导定向耦合器进行仿真优化,结果表明该耦合器性能优异,在0.35-0.36THz 频段内,隔离 度优于40dB,各端口的回波损耗大于40dB,插入损耗小于0.2dB。本文所设计的分支波导定向耦合器结构简单紧凑、性 能优越,具有广阔的应用前景。     

多孔波导定向耦合器DE理论化精确设计

一、引言贝蒂(Bethe)的小孔耦合理论,对解决波导之间的小孔耦合问题,有着重大的理论意义,但无实用价值。为了使该理论能用于有限厚度的大孔耦合,科恩(Cohn)提出了大孔修正因子、耦合波衰减因子和经验壁厚修正因     

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...     

（英）高效锥形太赫兹耦合器

设计了将太赫兹波耦合进入波导的耦合器.耦合器由金属材料铝制成,形状为中空圆锥形和圆柱形的结合.在宽带的脉冲太赫兹信号和单频的连续太赫兹信号两种情况下,模拟并实验测试了耦合器将自由空间传输的平行太赫兹波耦合进入反谐振波导,结果显示该耦合器是宽带太赫兹波耦合器.通过优化耦合器几何参数,在太赫兹时域系统下得到振幅耦合率达到71%,振幅增强因子为6.125.     

太赫兹辐射源与波导耦合研究新进展

对国际上关于半导体太赫兹辐射源和太赫兹传输波导之间的耦合问题的研究进展和最新动态进行了较详细的分析和归纳总结.太赫兹频段是一个非常有科学价值电磁波频段,它在信息科学,天文学、医学、环境科学、国防等领域都有广阔的应用前景和应用价值.太赫兹的应用除了太赫兹辐射源,太赫兹传输器件,太赫兹探测器等关键器件之外,还必须解决太赫兹辐射源和太赫兹传输器件之间的耦合问题.     

X波段高功率宽带波导定向耦合器设计

给出了一种X波段高功率宽带波导定向耦合器的工程设计方法。通过高频结构优化软件仿真,给出了影响耦合度指标的主要尺寸变化规律。仿真设计结果为:在f0±350 MHz内耦合度61 d B,带内起伏0.5 d B,方向性大于20 d B。     

弱耦合波导定向耦合器的计算机辅助设计

论述了波导定向耦合器的设计原理,设计思路,介绍了在计算机上利用FORTRAN语言对定向耦合器耦合孔进行计算,从而得到一种简捷的定向耦合器的设计方法。     

Improved directional couplers for overmoded waveguide systems

The performance of multihole directional couplers can be considerably improved by placing a second hole structure to the existing one. The improvement may be aimed at directivity or at suppression of certain unwanted modes propagating either in forward or backward direction.     

Mode selective directional couplers for overmoded waveguide systems

Two types of directional couplers for transverse electric (TE) modes are described: short and multihole couplers, respectively. They selectively pick one mode out of a mode mixture in an overmoded circular waveguide system. Unwanted modes are either statistically kept at low level or are suppressed by destructive interference in the coupling waveguide. Mode selectivity and directivity in multihole couplers oscillate up and down with an increasing number of holes, finally reaching a minimum of approximately 20 dB, unless there are competing modes with rational fractions of the beat wavelength. A multihole coupler for the TE₀₂ mode (28 GHz, 63.4 mm waveguide diameter, 41 holes) and a length of 1.6 m shows a calculated directivity of 68 dB and suppresses the unwanted modes TE₀₁ with 34 dB (24 dB), TE₂₂ with 37 dB (45 dB), and further modes TE_?m (?<5, m<6) with 17 dB to 34 dB in forward direction (figures in parentheses are for unwanted modes propagating in backward direction). A short directional coupler for the TE₀₁ mode (28 GHz, 63.4 mm waveguide diameter) with 16 holes and a length of 230 mm shows a directivity of 55 to 100 dB between 27.9 and 28.1 GHz, suppressing the TE₀₂ mode with 35 to 80 dB, the TE₀₃ mode with 30 to 65 dB, and the TE₂₂ mode with 30 to 70 dB.     

Broad-band high-silica optical waveguide star coupler withasymmetric directional couplers

A broadband optical waveguide star coupler with asymmetric directional couplers is proposed. A coupling or splitting ratio of the coupler is flattened with respect to wavelength by choosing appropriate values for Δβ and complete power transfer length. The wavelength characteristics of uniform and alternating Δ&thetas;b directional couplers are investigated, and their broadband operation is shown theoretically. To demonstrate the feasibility of the new proposal, 8×8 star couplers composed of such asymmetric directional couplers are fabricated by using high-silica waveguides on a silicon chip. A star coupler composed of asymmetric directional couplers exhibited 2-dB loss variation in the wavelength range of 1.3-1.55 μm, and this value was almost one fourth of that of a star coupler composed of symmetric directional couplers     

平行耦合线定向耦合器的设计

阐述了平行耦合线定向耦合器的工作原理和设计过程.根据耦合微带线和耦合带状线的主要特征,分别设计了频率为2.5GHz的平行耦合微带线定向耦合器和平行耦合带状线定向耦合器.根据给定耦合器的技术指标,确定耦合器的类型、结构.利用ADS软件环境设计了平行耦合线定向耦合器的电路模型,并对定向耦合器的S参数进行仿真、优化,已达到预期的设计要求.由仿真结果可以看出,在频带范围内,耦合带状线定向耦合器的耦合性能优于耦合微带线定向耦合器.     

Theoretical and experimental research on nonradiative dielectric waveguide directional couplers

A practical design of nonradiative dielectric (NRD) waveguide directional couplers is presented. The dispersion characteristics of coupled NRD-guides and the scattering coefficients of NRD-guide directional couplers are studied as well as the transitions from metal rectangular wave-guide to NRD-guide couplers. Experiments of 3-dB and 10-dB NRD-guide couplers in ka-band show that the couplers are of good performance and promise in millimeter-wave integrated circuits.     

Design of waveguide narrow-wall short-slot couplers

It is shown that the broad-band coupling properties of narrow-wall short-slot directional couplers and hybrids are due to the effect of the evanescent TE₃₀ mode in the coupling region. This causes a change to the effective phase length of the even-mode circuit, especially when a central tuning element is used. Using the results of a previous paper on the formation of an equivalent circuit from the generalized scattering matrix, an equivalent circuit for the even mode of the coupler is formed, clearly depicting the effect of the TE₃₀ mode     

Design data for interdigital directional couplers

The letter presents graphical information relating the performance of interdigital microstrip directional couplers to the geometrical parameters of the circuit. The theoretical background is summarised, and a comparison is made with reported experimental results.     

IMPROVED MODE-MATCHING AND NETWORK ANALYSIS OF E-PLANE WAVEGUIDE BRANCH DIRECTIONAL COUPLERS

The E-plane waveguide branch directional couplers are analyzed by a method which combines the multimode network theory with rigorous mode-matching approach. The electromagnetic field components are expanded by the superposition of LSEx modes rather than TE and TM modes in the mode-matching procedure. Meanwhile, the electromagnetic problem is transferred into the network problem through the mode-matching treatment. It is shown that the present method has the advantages of simplicity and less computation without affecting the accuracy of the calculation.     

Up and down UV-trimming of planar directional waveguide couplers:modeling

In contrast to etched channel waveguide couplers, directional couplers UV-written into a photosensitive layer can be both down and up trimmed by UV post-illumination of the waveguide cores and of the separating photosensitive region, respectively. Theoretically, the coupling length can be corrected by 10%-40% several times, before the third supermode starts to propagate     

Design and performance of groove-guide directional couplers

An approximate closed-form expression for the calculation of the coupling properties of groove-guide directional couplers is deduced from an exact analysis and confirmed by measurements.