具有谐波抑制特性的小型化分支线耦合器

提出了一种具有谐波抑制特性的小型化分支线耦合器。通过分析枝节加载传输线的传输特性,发现可以采用小型化的枝节加载传输线去等效替换传统分支线耦合器中的四分之一波长传输线,此方法可以极大地减小分支线耦合器的电路尺寸。同时,由于枝节引入传输零点,耦合器的谐波响应也得到抑制。为了验证理论分析的有效性,建立了等效电路模型和传输线方程,对电路性能进行分析,最后进行了仿真以及实验验证。     

一种新型小型化双频分支线耦合器的设计

设计了一款新型的小型化双频分支线耦合器。通过在端口处加载一段扩展的传输线实现分支线耦合器的双频工作。使用微带过渡结构连接不同介质层中的两个微带线电路以降低耦合器的尺寸。利用传输线理论将传统的λ/4 传输线等效为T 型传输线结构,并将端口处的扩展部分进行折叠处理,达到进一步缩减器件尺寸的目的。本文设计了一个工作频率在0. 97/1. 8GHz 的双频分支线耦合器,并进行实物加工,仿真结果性能良好,实测与仿真数据非常吻合。     

一种小型谐波抑制3dB分支耦合器的设计

基于分支线耦合器小型化和谐波抑制特性的要求,提出了一种小型谐波抑制分支线耦合器的设计方法,通过采用等效传输线理论和分形几何结构进行设计。基于此方法,设计了小型谐波抑制3 d B分支线耦合器,并对其进行了实物制作和测试。测试结果表明,该耦合器不仅实现了77.9%的尺寸缩减,而且具有5次谐波抑制的特性。与传统方法相比,设计方法具有尺寸小、谐波抑制特性好、易于制作和集成等优点,可以在无线通信系统中得到广泛应用。     

微带分支线定向耦合器的小型化

基于尺寸原因定向耦合器在微波电路中的应用受到限制,采用接终端开路短截线的方法使四分之一波长的微带线变成T型结构,并进一步对短截线等效成为十字型微带线的方法,设计出小型化的定向耦合器。通过使用ADS软件进行仿真,设计的定向耦合器各项性能指标符合要求,面积为常规微带分支线定向耦合器的36%。     

微波3dB微带双分支定向耦合器的小型化

分析理论上的3dB微带双分支线定向耦合的S参量特性。在此基础上,用接开路线的方法对标准3dB微带双分支线定向耦合器小型化,用奇偶模分析方法分析理论S参量特性,应用微带电路仿真软件ADS进行仿真,比较理论分析计算绘制的S参量特性曲线与仿真获得的S参量特性曲线,设计出小型化的微波频域3dB微带双分支线定向耦合器。     

具有宽频带的小型化双频分支线耦合器设计

针对当前通信系统需要耦合器支持多频段、小型化和高性能等要求,提出了一种双频(DB)分支线耦合器(BLC).通过在传统耦合器中间加非对称交叉耦合分支线同时实现了分支线耦合器的双频带和宽频带.非对称交叉耦合分支线的引入增加了设计的自由度.利用等效替换的方法实现耦合器的小型化.使用SBO(Surrogate-Based Op...     

微带双分支定向耦合器的小型化设计与实现

提出了小型化微带双分支定向耦合器的设计方案,通过对双分支微带线进行结构等效,解决了传统微带双分支定向耦合器尺寸较大的问题。应用HFSS软件对结构进行了优化仿真设计,并制作和测量了一款工作在L波段用于海事卫星通信的微带耦合器样件。该耦合器样件比传统双分支定向耦合器面积缩小了51%,实测结果与仿真结果吻合较好,验证了方案的可行性。     

基于DMRC结构的小型分支线耦合器设计

首先基于复合左右手传输线和微带缺陷结构提出了一种新型双螺旋微带缺陷谐振单元,并研究了其幅度特性和相位特性。然后,研究了其结构参数对传输特性的影响。最后,运用该新型双螺旋微带缺陷结构设计了一个小型化分支线耦合器,仿真及实测结果表明：该分支线耦合器不仅实现了62.8%的小型化,而且避免了后向辐射的问题。     

利用复合左右手传输线实现的两种平行耦合线定向耦合器

采用紧凑的复合左右手传输线模型实现了两种新型平行耦合线定向耦合器.第一种定向耦合器为六端口双定向耦合器,形式为右手传输线/复合左右手传输线/右手传输线,通过调整传输线与传输线之间的距离,实现一分三等分功率分配器的功能;第二种定向耦合器是在普通定向耦合器中,用部分复合左右手传输线代替右手传输线,通过调整它们之间的比例,可以使得耦合端和输出端的输出相位相等.设计的两种定向耦合器,均已通过实测验证.     

一种D波段小型化定向耦合器芯片设计

基于GaAs 0.1 μm pHEMT工艺,设计了一款工作在0.1~0.14 THz的小型化定向耦合器芯片。采用加载开路枝节线的方式提高传输线的等效电长度,进而实现电路结构的小型化;利用曲折线的方式构成开路枝节线,使得耦合器的物理尺寸进一步缩小。采用电磁仿真软件仿真表明,所设计的小型化定向耦合芯片中心工作频率为0.12 THz,相对带宽大于30%,带内的回波损耗高于20 dB,带内插入损耗小于1 dB,耦合度为(10±0.5) dB,带内隔离度大于20 dB,直通端口与耦合端口相位差为90°±3.5°,其尺寸为0.21 mm×0.19 mm(不计Pad尺寸)。     

Dual-Band, Unequal Length Branch-Line Coupler With Center-Tapped Stubs

A new dual-band branch-line coupler scheme is proposed based on the unequal length branch-line coupler structure and the center-tapped stub lines. The unequal length structure reduces the size of the dual-band branch-line coupler using center tapped stubs. Also, it offers the possibility of the stubless dual-band operation for some special cases, and the same phase relation can be obtained between the two output signals at the two frequency bands.     

A Stub Tapped Branch-Line Coupler for Dual-Band Operations

This letter presents a stub tapped branch-line coupler for dual-band applications. In the new design, a tapped stub is used to realize 90deg phase change at two frequencies. Both the characteristic impedance and the length of the proposed branch lines are adjusted accordingly compared with the conventional structure. Explicit design equations are derived using the ABCD-matrix. To verify the design concept, a microstrip coupler operating at 0.9 and 2GHz is fabricated and measured on a Rogers' RO4003 board     

A compact LTCC branch-line coupler UsingModified-T equivalent-circuit modelfor transmission line

In this letter, a compact branch-line coupler is proposed by making good use of the three-dimensional layout capability of the low-temperature co-fired ceramic (LTCC) substrate. This branch-line coupler is accomplished by using lumped-inductors and lumped-capacitors to realize the modified-T equivalent-circuit model for the transmission line so that the circuit size may drastically be reduced. Specifically, a very compact LTCC branch-line coupler with a size of 0.079/spl lambda//spl times/0.0717/spl lambda/ is implemented and carefully examined, where /spl lambda/ is the wavelength of the multilayer structure at the operating frequency f/sub 0/.     

Miniaturization of Microstrip Branch-Line Coupler With Dual Transmission Lines

The dual transmission lines are proposed to replace conventional quarter-wavelength transmission lines for a compact microstrip branch-line coupler in this study. The developed coupler can be easily fabricated on the printed circuit board without lumped element; moreover, its size is greatly reduced compared to the conventional branch-line coupler. Furthermore, simulated and measured frequency responses match well to validate the proposed coupler with dual transmission lines.     

Beam Forming Networks Using Reduced Size Butler Matrix

Recent trend shows that the reduced size couplers are becoming potential building blocks and have created a continuing demand for the growing wireless communications market. Therefore, this paper presents a new design and realization for reducing the size of the branch-line coupler using eight two-step stubs that operates at 2.45 GHz. In this study, the reduced size branch-line coupler has been implemented on a 4 × 4 Butler Matrix, which generally consists of branch-line coupler, crossover, and phase shifter. The simulation results are obtained by using the advanced design system (ADS) in terms of S-Parameter analysis and the phase difference between the ports. Moreover, this design is realized on a low-cost substrate, e.g., flame resistance board (FR4 Board). The obtained results show that the proposed design has reduced the electrical length of transmission line up to 50% and consequently, the area of the branch-line coupler has been reduced up to 30% from the normal size.     

Arbitrarily dual-band components using simplified structures of conventional CRLH TLs

Microwave components with nonlinear phase responses are developed using a simplified composite right/left-handed (CRLH) transmission-line (TL) structure without the series capacitance or the shunt inductance. Using such a simplified CRLH structure, arbitrarily dual-band microstrip components have been realized in compact sizes such as a quarter-wavelength short-circuited stub and dual- band branch-line couplers. Simulation and measurement results are given to demonstrate the efficiency and good performance of the proposed components. For the quarter- wavelength short-circuited stub based on the simplified CRLH-TL structure without the series capacitance, it has been shown that the insertion loss is less than -0.1dB. For the arbitrarily dual-band branch-line coupler, experiment results exhibit that S/sub 21/ and S/sub 31/ are larger than -3.6dB, the isolations are smaller than -30dB, the return losses are smaller than -20dB, and the phase differences are within 90/spl deg//spl plusmn/1.8/spl deg/.     

A compact coupler design using meandered line compact microstrip resonant cell (MLCMRC) and bended lines

Wireless Networks - In this paper, a novel branch-line coupler using meandered line compact microstrip resonant cell (MLCMRC) and bended lines is proposed. The presented coupler works at...     

Arbitrary dual-band components using composite right/left-handed transmission lines

Arbitrary dual-band microstrip components using composite right/left-handed (CRLH) transmission lines (TLs) are presented. Theory, synthesis procedure, and implementation of the dual-band quarter-wave (/spl lambda//4) CRLH TL are presented. Arbitrary dual-band operation is achieved by the frequency offset and the phase slope of the CRLH TL. The frequency ratio of the two operating frequencies can be a noninteger. The dual-band /spl lambda//4 open/short-circuit stub, dual-band branch-line coupler (BLC), and dual-band rat-race coupler (RRC) are also demonstrated. The performances of these dual-band components are demonstrated by both simulated and measured results. Insertion loss is larger than 23 dB for the shunt /spl lambda//4 CRLH TL open-circuit stub and less than 0.25 dB for the shunt /spl lambda//4 CRLH TL short-circuit stub at each passband. The dual-band BLC exhibits S/sub 21/ and S/sub 31/ larger than -4.034 dB, return losses larger than 17 dB, isolations larger than 13 dB, phase differences 90/spl deg//spl plusmn/1.5/spl deg/, and gain imbalance less than 0.5 dB at each passband. The dual-band RRC exhibits S/sub 21/ and S/sub 31/ larger than -4.126 dB, return losses larger than 12 dB, isolations larger than 30 dB, phase difference 180/spl deg//spl plusmn/4/spl deg/, and gain imbalance less than 0.2 dB at each passband.