共面波导馈电的小型化双通带滤波器

提出了一种采用共面波导馈电的小型多模双通带平面滤波器,该滤波器采用内部嵌套的多模谐振器缩小了电路尺寸,利用奇偶模分析方法和弱耦合激励的方式分析了该多模谐振器的谐振特性,并依此推导出其谐振频率与物理尺寸的相互关系。为了满足滤波器的馈电,端口耦合并实现小型化,引入了异面共面波导馈电结构。文中给出了四个谐振模式的分析以及两个通带中心频率和带宽的控制机理,实现了滤波电路的频率和带宽的独立控制。最终实现了中心频率为2.39GHz 和4.34GHz,相对带宽分别为8.8%和13.4%的双通带平面滤波器。该滤波器中心频率和带宽独立设计可控,而且谐振器尺寸大小仅为0.09λg ×0.09λg 。本文所设计的滤波器结构简单、尺寸小,通带间隔离度较高、易加工制作,具有较高实用价值。     

基于L型槽结构的小型化SIW滤波器

为了解决传统基片集成波导(SIW)滤波器在通信电路中占用空间较大的问题,提出一种新型的开槽方法实现了小型化SIW滤波器.通过在四分之一模基片集成波导(QMSIW)谐振腔的顶层金属板上蚀刻L型谐振槽,利用开槽扰动的模移技术原理,使QMSIW腔的谐振基模被移动到低频处.基于此,设计了一款中心频率为2.6 GHz,相对带宽为...     

宽带基片集成波导滤波器

滤波器是微波毫米波电路与系统中一个重要的部件.提出了一种CMRC加载基片集成波导( substrate integrated waveguide,SIW)滤波器.该滤波器具有体积小、重量轻、容易加工和集成等优点.滤波器的中心频率为5.3 GHz,相对带宽为36%,中心频率处的插入损耗为1.5 dB,仿真与实验结果吻合良好.     

一种新型小型化Ka波段波导带通滤波器的研制

设计了一种新型的小型化Ka波段波导带通滤波器。为了增加滤波器的带外抑制能力,在波导带通滤波器中设计插入了一个销钉。通过分析波导中销钉的等效电路,对加入销钉的滤波器进行了电磁场仿真设计。仿真结果表明,插入销钉的滤波器在高端引入了一个传输零点。按照仿真结果设计制作了波导带通滤波器,测试结果表明,该结构在保证性能指标的基础上有效的减小了波导滤波器的尺寸。该滤波器具有插入损耗低、零点位置调配灵活、体积小等优点。     

半模基片集成波导带通滤波器的设计与实现

简要介绍半模基片集成波导这一新技术,设计了一个中心频率为35GHz,相对带宽为23％的基片集成波导带通滤波器,CST的数值计算结果显示该途径是成功的.     

阶跃阻抗滤波器及其倍频应用

阶跃阻抗谐振结构(SIR)是一种新型微带线结构,它具有小型化,尺寸易调整,寄生谐振频率可调等优势.本文利用一种半波长阶跃阻抗谐振结构设计了两个不同尺寸发卡形滤波器,获得同样优秀的性能指标.而后利用此类滤波器完成了一个倍频电路的设计并且达到预期要求.     

基片集成波导带通滤波器的设计与实现

基片集成波导技术使得包括平面电路、接头和矩形波导在内的完整电路可以以平面形式集成在印刷电路板上;首先简要介绍基片集成波导这一新技术,然后把矩形波导带通滤波器的设计方法引入基片集成波导中,设计了一个中心频率为35 GHz,相对带宽为2.7%的基片集成波导带通滤波器,CST的数值计算结果显示该途径是成功的。     

具有小型化与高选择性的双频带通滤波器的设计

为了满足C波段卫星通信系统的应用需求,提出了一种具有小型化与高选择性的双频带通基片集成波导滤波器. 滤波器第一通带由蚀刻在四分之一模基片集成波导腔顶层的L型谐振槽提供,第二通带由新型左右手结构提供. 其中L型谐振槽可以充当四分之一波长谐振器,激励腔内基本模式产生低频处的响应;新型左右手结构较传统结构增大了叉指电容值,降低了谐振频率. 通过仿真优化和测试,双频带通滤波器的中心频率为3.9 GHz和6.2 GHz,相对带宽为3.3%和2.1%,通带之间的衰减优于70 dB,且在通带外存在三个传输零点,具有良好的频率选择性. 表明了所提滤波器具有体积小、选择性高的特性,非常适合集成于卫星通信前端系统中.     

一种基于介质集成波导腔的小型化滤波器

为了实现介质集成波导滤波器的进一步小型化,通常要改进其谐振腔;通过在传统的介质集成波导谐振腔中心位置插入一个短路销钉,并且将其上金属平面与腔体四周的金属壁绝缘可以实现其体积的小型化.采用这种小型化谐振腔,设计了四腔微带滤波器,工作在2.8 GHz,相对带宽14.3％.最终加工了这个原型滤波器,仿真和测试结果吻合良好.相比采用传统的介质集成波导谐振腔的滤波器,这个滤波器尺寸可以减小到其1/4以下.     

一种新型基片集成波导腔体滤波器的设计与实现

滤波器是微波毫米波电路与系统中一个重要的部件。利用基片集成波导(substrateintegratedwaveguide——SIW)技术设计并用印制电路板实现了一种应用低阻-高阻短微带线作补偿的基片集成波导滤波器,仿真与实验结果吻合良好,中心频率为5. 8GHz,相对带宽4. 95%,插损小于1. 3dB。该滤波器具有具有体积小、重量轻、容易加工和集成等优点。     

A Novel Band-Reject Element for Pseudoelliptic Bandstop Filters

A novel band-reject element for the design of inline waveguide pseudoelliptic band-reject filters is introduced. The element consists of an offset partial-height post in a rectangular waveguide in which the dominant TE₁₀ mode is propagating. The location of the attenuation pole is primarily determined by the height of the post that generates it. The element allows the implementation of weak, as well as strong coupling coefficients that are encountered in asymmetric band-reject responses with broad stopbands. The coupling strength is controlled by the offset of the post with respect to the center of the main waveguide. The posts are separated by uniform sections of the main waveguide. An equivalent low-pass circuit based on the extracted pole technique is first used in a preliminary design. An improved equivalent low-pass circuit that includes a more accurate equivalent circuit of the band-reject element is then introduced. A synthesis method of the enhanced network is also presented. Filters based on the introduced element are designed, fabricated, and tested. Good agreement between measured and simulated results is achieved     

Monolithic millimetre-wave oscillator using a transmission lineperiodically loaded by QWITT diodes

A small-signal analysis of a travelling-wave structure implemented by periodically loading a parallel-plate waveguide with either resonant tunnelling or QWITT diodes is presented. A small-signal equivalent circuits is used to determine the diode impedance as a function of frequency. The periodicity of the structure, i.e. the distance between adjacent diodes, determines the oscillation (resonant) frequency of the circuit. The analysis shows that change in the oscillation frequency through variation in the design width and thickness of the waveguide is minimal. The physical dimensions of the waveguide facilitate monolithic fabrication of the oscillator circuit     

On the Fast and Rigorous Analysis of Compensated Waveguide Junctions Using Off-Centered Partial-Height Metallic Posts

In this paper, we present an efficient and rigorous method, based on the 3-D boundary integral-resonant-mode expansion technique, for the analysis of multiport rectangular waveguide junctions compensated with partial-height cylindrical metallic posts. The electrical performance of a great variety of commonly used wideband microwave circuits has been improved drastically thanks to the introduction of a new design parameter, i.e., the relative position of the metallic post in the structure. To the authors' knowledge, this parameter has not been taken into account in previous studies concerning compensated junctions using partial-height metallic posts. The developed tool has been successfully used to design compensated H- and E-plane right-angled bends and power dividers, as well as optimal magic-T junctions. This novel tool has been fully verified through comparisons between our results and those provided by a well-known commercial finite-element method software     

基于SIW-CSRR的固体物质介电常数测试件设计

为满足当前固体物质介电常数的检测需求,在基片集成波导(SIW)的基础上加载互补开口谐振环(CSRR),设计了一款固体物质介电常数测试件,讨论了利用测试件谐振频率的偏移检测固体物质介电常数的可行性。仿真与测试结果表明,当检测物质相对介电常数从1变化至10时,测试件谐振频点从7.56 GHz 偏移至6.28 GHz,偏移量达1.28 GHz。利用谐振频点与测试样品介电常数的关系,测量了5种常见电路板材的相对介电常数,其相对误差均低于3%。     

A rigorous modal analysis of H-plane waveguide T-junction loadedwith a partial-height post for wide-band applications

A rigorous modal analysis (MA) for the H-plane waveguide T-junction loaded with a partial-height conducting post is presented in this paper. The analysis is based on the classical resonator mode-matching technique for waveguide junction problems and a novel concept called extended eigenmode functions. The new concept can be used for constructing eigenmode functions of a complex resonator region as long as the modal solution for a subproblem is available. Particularly for the T-junction problem, the modal solution for the two-port in-line waveguide loaded with the post is used. The proposed MA has been extensively verified by a finite-element method software package. Excellent agreement can be observed. Numerical results obtained by the analysis reveal that by adjusting the dimension of the loading post, the usable band width of the T-junction for constructing a diplexer can be significantly expanded. Since the generalized scattering matrix is obtained, the proposed analysis can be integrated with other available waveguide key building-block models for system analysis     

Resonant length of longitudinal slots and validity of circuit representation: Theory and experiment

Pertinent theory for the design of longitudinal slot arrays is reviewed and its dependence on the dominant mode scattering off a single slot is pinpointed. The critical need to know resonant length versus slot offset is emphasized and the desirability of determining this information theoretically rather than experimentally is argued. Then method of moments solutions are used to calculate resonant length versus slot offset for given waveguide dimensions and frequency. These theoretical results are compared to new, carefully obtained experimental data. Agreement is found to be so good, it is concluded that one can dispense with the costly gathering of experimental input data when designing longitudinal slot arrays fed by standard rectangular waveguide. A critical look is taken at the validity of representing the longitudinal slot as a shunt element on an equivalent transmission line. This assumption is found to be more and more questionable as thebdimension is reduced. For quarter-height guide, an alternate design procedure is suggested as being more accurate.     

A 50 GHz broad-band monolithic GaAs/AlAs resonant tunneling diodetrigger circuit

This paper describes the design, circuit simulation, fabrication and testing of a 50 GHz trigger circuit using GaAs/AlAs resonant tunneling diodes. A new trigger circuit was designed to eliminate the 180° phase splitter used in a previous complementary input trigger circuit. Our monolithic approach, integrated GaAs/AlAs resonant tunneling diodes (in a back-to-back configuration) and a 50 Ω coplanar waveguide, minimized the parasitic circuit elements and internal reflections from the package thus achieving high frequency operation. The circuit was able to trigger on input sinusoidal waves of input powers of -3 dBm up to 50 GHz with time jitter of less than 1 ps rms over the entire measured frequency range from 5 to 50 GHz. The upper limit of 50 GHz was imposed by our measurement system     

Harmonic operation of GaAs millimetre wave transferred electron oscillators

Harmonic operation of GaAs millimetre wave transferred electron (TE) oscillators has been identified using a wideband waveguide system. The harmonic number was determined by precisely measuring the frequency as well as the frequency variations of the harmonic components when the oscillator was tuned mechanically or electrically. We find that GaAs TE oscillators at 94 GHz, matched to a waveguide circuit by means of a resonant disc, operate at the second or third harmonic frequency, depending on the length of the active GaAs region, which was between 1.8 and 2.6 ?m.     

Field theoretical treatment of E-plane waveguide junctionswith anisotropic medium

E-plane waveguide junctions containing an anisotropic medium are analyzed. The analysis is based on the equivalence principle and on cavity field expansions. Using the equivalence principle, magnetic surface currents are introduced at the imaginary boundaries chosen between the central region of the junction and the waveguides. The electric displacement D in the junction is expressed in terms of a solenoidal set and an irrotational set. Matching the tangential magnetic field at the imaginary boundaries leads to a matrix equation, the unknown of which are the amplitudes of the scattered waveguide modes. Using this method, the performance of E-plane waveguide junctions with full-height and partial-height ferrite post is analyzed. The influence of the completeness terms G_oq on the numerical results of an empty E-plane Y-junction is shown. The numerical results are compared with previously published experimental and theoretical results     

Efficiency optimization for systems and components in microwave power engineering.

The paper is concerned with one aspect of optimization of microwave thermal processing, namely, with optimization of energy coupling interpreted as a numerical characteristic of system efficiency. Since in computer-aided design coupling can be evaluated through the computed reflections, an optimization scheme is presented that is particularly suitable for minimizing the reflection coefficient in typical systems and elements of microwave power engineering. Based on response surface methodology and the sequential quadratic programming for constrained optimization, the procedure is linked with the full-wave 3-D FDTD electromagnetic simulator QuickWave-3D. Credibility and effectiveness of the method is illustrated by four examples: dimensional optimization is performed for a dry waveguide load, a waveguide T-junction with a partial-height post, a water cylinder in a cavity, and a slotted waveguide-backed radiating element.