一种紧凑型LTCC差分分支线耦合器

为满足微波电路高集成度以及抑制电磁串扰的需求,通过在低温共烧陶瓷(low temperature co-fired ceramic,LTCC)不同层分布具有特定奇模特性阻抗耦合线的方式实现了一种紧凑型差分分支线耦合器.一方面,耦合线在保证差模传输的基础上具有相对集中电场分布的特性,因此可以在LTCC中相互重叠,从而有效减小尺寸;另一方面,耦合线与单条带状线相比可以减少接地层的使用,从而降低损耗.为验证理论预期可行性,设计了一个工作在1.84 GHz频率下,尺寸为0.07λg×0.07λg(λg为中心频率的导波波长)的LTCC差分分支线耦合器.实测结果表明,最小插入损耗为0.6 dB,15 dB回波损耗的相对带宽和隔离带宽分别为18.2％、18.0％,±10°相位差的相对带宽为40.0％.本文设计具有尺寸小、损耗低、带宽增强和易于与差分芯片连接等优点,可以作为一种实用的微波器件.     

A compact branch-line coupler using discontinuous microstrip lines

We introduce a branch-line coupler using discontinuous microstrip lines whose size is significantly reduced relative to the standard design. We manipulate the reactive characteristics of discontinuities in its microstrip lines to achieve a physical size reduction of almost 60% with comparable performance.     

Broadband microstrip branch-line coupler Broadband microstrip branch-line coupler

The design and measured performances of a broadband branch-line coupler are presented. The broadband coupler was designed by using a four-section branch line topology with a structure of the defected ground. Such a structure can make the impedance of the microstrip line much larger than that without defected structure, even using a normal PCB process. More than 231 Omega was easily achieved by such a defected structure. The measured performance of the broadband coupler agrees well with the results from simulation     

A novel compact-size branch-line coupler

A novel compact-size branch-line coupler without any implementation of lumped-elements, bonding wires, and via holes is proposed. In this study, the size of the proposed coupler occupied only 45% of the conventional branch-line coupler at 2.4GHz. The performances of the circuit can be competed with the conventional coupler. The element sizes of this coupler can be realized easily by using simply standard printed-circuit-board etching processes. It is very useful for applications in the wireless communication systems.     

Miniaturization and harmonic suppression branch-line coupler using short-circuit anti-coupled line

In this article, short-circuit anti-coupled lines structure is applied to design a miniaturised microstrip branch-line hybrid coupler. The proposed structures can achieve both a significant reduction of size and harmonic suppression. As the short-circuit anti-coupled lines structure is constructed entirely from microstrip lines, the couplers can be easily fabricated using conventional printed-circuit board process. The performance of the proposed couplers is as good as that of the conventional structures and deep harmonic suppression in addition. The design and simulation have been performed using full-wave analysis based on ADS Momentum.     

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%。     

A compact quadrature coupler based on coupled artificial transmission lines

A new compact quadrature hybrid based upon artificial transmission lines (ATLs) is presented. Miniaturization is achieved through reduced even- and odd-mode phase velocities which are achieved using capacitive loading with interdigital open-circuited stubs. A proof-of-concept microstrip implementation of the quadrature hybrid exhibits performance comparable to a conventional branch-line coupler while occupying only 14% of the area. The compact structure of the hybrid is useful for RF applications and is suitable for scaling to frequencies above 100GHz where the size of shielded-microstrip components must be limited to prevent excitation of high-order modes.     

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。     

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...     

Independently-tuned concurrent dual-band branch-line coupler using varactor

This paper presents a concurrent dual-band branch-line coupler with an independently tunable center frequency.In the proposed architecture,the quarter-wavelength lines,which work at two separated bands concurrently and can be tuned in one of them,are key components.Based on the analysis of ABCD-matrix,a novel hybrid structure and a pair of varactors topology are utilized to achieve concurrent dual-band operation and independent tunability,respectively.Using this configuration,it is convenient to tune the center frequency of the upper band,while the responses of the lower band remain unaltered.To verify the proposed idea,a demonstration is implemented and the simulated results are presented.     

Dual-band rat-race coupler design using tri-section branch-line

The design of a novel rat-race coupler that can operate at two widely separated frequency bands is presented. The proposed circuit also features compact size, planar structure without a via hole, and low insertion loss. For validation, both simulated and measured performance of a microstrip rat-race coupler operating at 2.45/5.8 GHz are shown     

A novel approach to the design and implementation of dual-band compact planar 90/spl deg/ branch-line coupler

This paper presents the design of a novel branch-line coupler that can operate at two arbitrary frequencies. The proposed circuit also features compact size and planar structure. Explicit design formulas of the proposed dual-band coupler are analytically derived. Moreover, practical issues such as the realization of branch-line impedance and optimum choice of circuit topologies are addressed. For verification purposes, both simulated and measured results of a microstrip branch-line coupler operating at 900/2000 MHz are included.     

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...     

Miniaturisation and harmonic suppression of the branch-line hybrid coupler

In this article, two compact structures of the branch-line hybrid coupler (BLC) which can suppress upper order harmonics of the conventional BLC are proposed. By replacing the microstrip transmission lines at any electrical length of the conventional BLC with their equivalent new T-type transmission lines, two compact BLCs that can suppress upper order harmonics are achieved. Design equations of the proposed T-type line are achieved by ABCD matrices. To validate the design concept, first, a compact BLC which utilises a proposed T-type line in each of its branch is designed and fabricated to suppress the second to the eighth harmonics. Furthermore, the first BLC is analysed by even- and odd-mode analyses and the scattering parameter matrix of the first BLC is calculated at the first to eighth harmonics. There is an excellent agreement between simulated and measured results. Then, a compact BLC which uses two proposed T-type lines in each of its branch is designed at 1?GHz to suppress the second to the fifth harmonics and the second to sixth harmonics, simultaneously. The first- and second-proposed structures are 50% and 46% of the conventional BLC, respectively, while maintaining the characteristics of the conventional BLC at the fundamental frequency.     

A PIN diode controlled variable attenuator using a 0-dB branch-line coupler

We describe a simple PIN diode controlled variable attenuator that employs a 0-dB branch line directional coupler. The response of the attenuator was measured between 1.3 GHz and 2.6 GHz. At the center frequency, the attenuation monotonically varied from 0.7 dB to 23 dB with the control voltage, and the distributed branch-line coupler structure resulted in low input reflection. Our attenuator is easier to design, smaller in area than a double hybrid coupled attenuator, and has comparable or better reflection and attenuation performance characteristics.     

High frequency microstrip branch-line coupler design with T-junction discontinuity compensation

A design procedure has been developed for high frequency microstrip branch-line couplers. The performance of these couplers is improved when T-junction discontinuity effects are compensated.     

基于互补分裂谐振环的十字缝隙贴片天线（英文）

A compact patch antenna is designed, which is with structures of cross-shape slot, Complementary Split Ring Resonator(CSRR), and loaded transmission line. To implement the compactness in size, these structures are etched on the ground plane, then the input impedance has been improved. The CSRR is employed to improve impedance matching between the source and radiation patch, and the cross-shape slot on the radiation patch is utilized to increase the bandwidth. The design is validated by compariso...     

Vehicle mounted coupler response via a multiple-sectioned wayside transmission line

The frequency response of a vehicle mounted coupler via a multiple-sectioned long transmission line is obtained by computer simulation. This paper presents a method of computation and two example results. The results may be used to investigate the transmission properties of wayside communication links.     

A new compact LTCC bandpass filter using negative coupling

This letter presents the design and realization of a new compact bandpass filter (BPF) fabricated on multilayered ceramic substrates. This BPF features coupled resonators with negative coupling coefficients. A BPF with center frequency 2.45 GHz is designed and fabricated. Its size is only 2.0 mm/spl times/1.8 mm/spl times/0.67 mm when implemented by a standard low temperature co-fired ceramic technology. The size reduction is due to the higher coupling coefficient between the negatively-coupled resonators than the positively-coupled ones, allowing tighter space between the resonators. The measured insertion losses of the previous BPF were less than 3dB and return losses more than 18dB in the passband. The measured result agrees very well with the electromagnetic (EM) designed response.     

光电耦合器在并口长线传输中的应用

提出了一种利用高速光电耦合器提高并口传输距离的方法,利用光电耦合嚣对传输线进行隔离处理,大大提高信噪比.讨论了光电耦合器的特性和选取原则,试验结果表明:这种方法能够在保持并口传输的速度优势以及系统结构不变时,保证信号传榆的准确性,具有较大实用价值.