提高声表面波滤波器带外抑制的一种方法

提出了一种提高非对称频响声表面波滤波器带外抑制的方法，即采用特殊设计的多条耦合器加吸声介质；接收叉指换能器选取适当加权，得到更低的旁瓣电平。这些措施使声表面波滤波器的带外抑制提高到－４５ｄＢ以上，陷波点－５５ｄＢ以上，矩形系数也大为改善     

电话耦合器及其实际应用

文中介绍了一种电话耦合器的基本原理和特点，给出了电话耦合器在新闻报道，现场，热线交流等场合的实际应用。     

L波段小体积微带监测耦合器设计研究

提出了一种用于1/8监测网络的微带线定向耦合器,该微带线定向耦合器结构在传统的微带线定向耦合器两端加入补偿电容,具有高定向性,给出了物理模型,对该结构进行了理论分析,并设计制作和测量了该种耦合器。测量结果表明,该定向耦合器的耦合度为26dB,工作频带为1.2～1.4GHz,隔离度超过-53dB,性能指标明显优于传统结构的微带线定向耦合器。同时减小了微带线定向耦合器的尺寸。     

X波段微带线定向耦合器的设计与模拟

提出了一种在X波段工作的高定向性的微带线定向耦合器结构,该结构在微带线两端和中间同时加入补偿电容以实现高定向性;随后我们分析了该种定向耦合器,推出了计算它的一系列表达式;最后通过ADS软件模拟得出了用该结构设计出的7dB定向耦合器的S参量,在12GHz中心频率下S11、S21、S31和S41分别为-44dB、-0．968dB、-6．997dB和-43．68dB,从而验证了理论分析的正确性。     

一种超宽带耦合带线3dB耦合器设计

本文介绍了一种超宽带耦合带线3dB耦合器的设计.通过10%的加工公差仿真设计表明该种耦合器具有优良的性能.实际的设计结果在1.2～4.2GHz频带内插入损耗小于0.5dB,带内波纹大于-0.25dB小于 0.35dB,端口隔离大于17dB,端口驻波小于1.3.文章还对该种耦合器的峰值功率容量进行了分析,为其高功率应用提供了依据.     

波导H-T纵向双缝耦合器的矩量法分析

提出一种波导H-T双缝耦合器,并用矩量法对其进行了分析计算,结果表明这种耦合器反射系数小、耦合度频响特性好,优于单缝耦合器。     

波导H-T纵向双缝耦合器的研究

提出一种波导H－T双缝耦合器,并用矩量法对其进行了分析计算、结果表明这种耦合器反射系数小、耦合度频响特性好,优于单缝耦合器。     

一种新颖三元件补偿的微带线定向耦合器研究

提出了一种在传统的微带线定向耦合器两端和中间分别加入补偿电容(简称三元件补偿)的具有高定向性、低插入损耗、低反射损耗和较宽带宽的微带线定向耦合器结构,给出了物理模型,对该结构进行了理论分析,并设计制作和测量了该种耦合器。测量结果表明,该定向耦合器的耦合度为20dB,工作频带为2.5～3.5GHz,隔离度超过-40dB,反射损耗低于-24dB,插入损耗优于-0.25dB,性能指标明显优于传统结构的微带线定向耦合器。     

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。     

Ka波段3dB定向耦合器的设计与仿真

定向耦合器广泛地用在现代微波系统中,文中介绍了两种应用在平衡式放大器中的3dB定向耦合器。首先对微带分支线耦合器与波导耦合器进行了理论分析,然后利用电磁仿真软件HFSS,对两种耦合器进行了建模仿真。仿真结果验证了这两种定向耦合器的可实现性,最后比较了两种耦合器的性能,并且总结了各自的特点。     

反射式光电耦合器速度测试技术研究

提出了一种基于光电耦合器的干扰弹速度测试方法：当干扰弹飞过炮筒时,光电耦合器发射光线照射到干扰弹的表面,漫反射回来的光被耦合器的探测器接收转变为电信号并采集到计算机进行数据处理。介绍了干扰弹测速系统的方案、工作原理及驱动电路,并测量了光电耦合器的响应速度和位置特性;最后利用本系统对干扰弹进行了模拟测试。试验证明：该系统响应速度快、抗烟雾干扰性强、使用方便。     

SAW Vestigial Sideband Filter for TV Broadcasting Transmitter

This paper reports the application of an SAW vestigial sideband (VSB) filter to a TV broadcasting transmitter. The filter requires steep cutoff characteristics and large fractional bandwidth. The X-112° Y · LiTaO/sub 3/ is one of the most suitable substrates for this filter, because it is possible to satisfy specifications without any compensation for typical temperature variations. The first application of LiTaO/sub 3/ substrates to a VSB filter is discussed in this paper. The filter is designed by a new optimization method using nonlinear programming. Because of the lack of a microstrip coupler and due to a large number of fingers, various second-order effects had to be compensated for. Experimental results are presented, when the filter is installed in a 10-kW TV transmitter.     

Directional coupler for gigahertz frequencies, based on the coupling properties of two planar comb transmission lines

The principles of operation are given for a directional coupler based on the coupling properties of two interleaved planar comb transmission lines. It is shown that this arrangement leads to a departure from a contradirectional coupling mechanism. Results are given for an X band ?3 dB coupler, and the performance and manufacturing methods are compared with those of other high-frequency coupler designs.     

Optimizing imbalance and loss in 2 /spl times/ 2 3-dB multimode interference couplers via access waveguide width

The imbalance and excess loss in multimode interference couplers with fabrication errors are examined. Remarkably, there exists a number of optimum access waveguide widths which give a minimum imbalance. Furthermore, quite low excess loss can be simultaneously achieved by choosing one particular optimum width. It is also shown that paired interference couplers have better imbalance performance than general interference couplers, given the same fabrication tolerances and length constraint for both coupler types. In particular, a paired interference coupler with an access waveguide width approximately 0.3 times the coupler width has the best imbalance performance. These results are obtained using a simple model and are supported by more sophisticated numerical models and experimental data from couplers fabricated in InP/InGaAsP.     

矢量网络分析仪反射测量误差分析与修正

本文介绍了定向耦合器在矢量网络分析仪反射测量中的作用,分析了定向耦合器导致方向性误差的原因:耦合端出现的信号中包含有泄漏过去的非理想信号,在定向耦合器的耦合端口是被测件反射的信号,是理想的被测信号,但实际的定向耦合器并不理想,一小部分信号在经被测件反射之前便泄漏到了耦合端口。耦合端口的信号中包含有泄漏过去的非理想信号,从而给被测件的反射测量引入了误差。文中给出了单端口误差模型以及误差修正的方法,并以某型手持式单端口矢量网络分析仪为例给出了经误差修正后测量精度的提升效果。     

Microstrip-Slot Coupler Design-Part I: S-Parameters of Uncompensated and Compensated Couplers

Using the even-odd mode analysis of four-port networks with double symmetry, the scattering parameters of the microstrip-slot coupler are derived from the even- and odd-mode parameters of the coupler cross section. The uncompensated coupler and the coupler compensated by extending the slot fines are treated and design specifications are given covering the compensation slot lines. A comparison with experimental data will be given in Part II.     

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...     

A COMPACT QUADRATURE FEEDING CIRCUIT FOR CIRCULARLY POLARIZED ANTENNA

A novel compact quadrature feeding circuit for a circularly polarized antenna is described. The equivalent circuit method in microwave network theory is used and the conventional directional coupler is converted to a new quadrature feeding circuit. This feeding circuit has the same characteristics as the conventional directional coupler but its size is only about one fourth of that of the latter. The formulas for designing the feeding circuit are given. The optimized results obtained by using the software ENSEMBLE are also reported.     

波导平面电路定向耦合器及CAD

本文利用平面电路耦合孔阵作为波导侧壁耦合的定向耦合器电路;该平面电路具有调节耦合度方便、加工简单、生产成本低的特点.本文给出了计算机辅助设计的方法和测试结果.     

A Plasma Controlled Directional Coupler

A new type of waveguide directional coupler is described which has a discharge tube as the coupling element in the common narrow wall between the guides. The use of the discharge tube allows continuous control of the amount of coupling between the guides. The theory of the coupler is given with curves for designing such a coupler. The paper describes the results obtained from a 3-db coupler. Measurements were made at a frequency of 450 Mc, of VSWR, noise output, and switching speed. These show a VSWR of the order of 1.3 over the control range, and an excess noise temperature with a peak of 20,000/spl deg/K at one value of control current. The coupler is capable of switching up to speeds of 1000 cps.