基于树状分形结构的半模基片集成波导带通滤波器

提出了一种基于分形结构的半模基片集成波导(HMSIW)滤波器。该设计将树状分形结构蚀刻在HMSIW的上金属表面,通过在其高频端引入宽阻带来产生带通效应。这种基于树状分形的HMSIW带通滤波器结构,随着迭代次数的增加,其相对带宽基本保持不变(S11<-15dB),但其带通边缘频响斜度变陡,且带外抑制特性不断增强。仿真结果与实验结果基本吻合,较好地验证了设计的可行性和有效性。     

集成宽带折叠半模基片集成波导带通滤波器

 本文提出并设计了一种新型的折叠半模基片集成波导（Folded Half-Mode Substrate Integrated Waveguide: FHMSIW）宽带带通滤波器,并给出了FHMSIW上层金属层槽缝式和中间金属层槽缝式宽带滤波器的仿真和测试结果。相对于半模基片集成波导（Half-Mode Substrate Integrated Waveguide: HMSIW）槽缝式滤波器,由双层PCB制作的FHMSIW槽缝式滤波器的尺寸减小了约一半。同时测试结果和仿真结果表明该宽带滤波器具有损耗小、带外抑制好等特性。     

新型半模基片集成波导镜像转接段的研究

本文提出了半模基片集成波导的镜像转接段设计,并对其功率分配方面的应用展开了研究.首先分析了半模基片集成波导应用于功分器设计的局限性,然后提出了通过镜像转接方式来实现具有双侧开口面的新型半模基片集成波导镜像转接段.通过仿真分析和实验测试验证了半模基片集成波导镜像转接段结构及其设计方法的可行性.最后设计了基于镜像转接段且具有对称结构的半模基片集成波导三路功分器.该功分器的仿真结果与实验数据表明,采用镜像连接段的半模基片集成波导器件具有良好的传输性能,有助于拓宽半模基片集成波导在功率分配网络设计方面的应用.     

Novel half-mode substrate integrated waveguide bandpass filters using semi-hexagonal resonators

In this paper, a novel bandpass filter is presented, designed, and implemented by using a triple mode semi-hexagonal Half-Mode Substrate Integrated Waveguide (HMSIW) cavity, which has the advantages of compact size, low insertion loss, and high selectivity in upper and lower passband. To realize a triple mode filter, the first resonant mode is shifted to near the next two modes using a via hole perturbation. Two microstrip open stubs connected to open edge of HMSIW resonator are introduced to generate two transmission zeros in the lower passband. The position of transmission zeros could be controlled by adjusting the coupling gap between the microstrip open stub resonators. By etching an E-shape slot on the top plate of HMSIW resonator, two other transmission zeros are produced in the upper passband. A wide-band planar six-pole bandpass filter, which has the advantages of wide bandwidth and small size, is also proposed and fabricated by cascading two triple mode resonators. Measured results indicate that 29% and 47% fractional bandwidth, as well as approximately 1 dB and 1.1 dB insertion loss, are achieved for the proposed filters. Measured results of all those filters agree well with the simulated results.     

A Novel Four-Way Ka-Band Spatial Power Combiner Based on HMSIW

In this letter, a simple low-loss planar spatial power-combining architecture based on half model substrate integrated waveguide (HMSIW) is proposed and studied. The power-combining structure is realized by transition between a HMSIW and parallel multiport planar microstrip lines. The power combiner is simulated and measured at 34.5–36.5 GHz. Measured results show a good agreement with simulation and a combining efficiency of 82% is achieved at 35 GHz.      

A Millimeter Wave Six-Port Network Using Half-Mode Substrate Integrated Waveguide

A novel six-port network based on half-mode substrate integrated waveguide (HMSIW) is proposed. In this design, a HMSIW hybrid 3 dB coupler and a -90° phase shifter are designed as fundamental building block of six-port network. By combining four HMSIW couplers and one phase shifter, a HMSIW six-port network at 29–32 GHz is constructed. The six-port network is fabricated and measured. Measurement results agree well with simulation, and show good balance and phase relationship between ports.     

一种新型半模基片集成波导三孔定向耦合器

半模基片集成波导(HMSIW)是近年来出现的一种高性能平面导波结构,具有传输损耗小、功率容量大、易于集成等优点,已开始广泛应用于微波无源器件的设计中。文章基于HMSIW技术与PCB工艺技术设计制作了一种新颖的三孔定向耦合器,通过在耦合孔上金属面蚀刻"工"字形槽增加孔的耦合量。设计的HMSIW三孔定向耦合器不仅保持了集成基片波导(SIW)定向耦合器的所有优点,而且在面积上减小了近50﹪,工作带宽拓展到1GHz。实测数据与仿真结果基本吻合,验证了设计方法的正确性与可行性。     

半模基片集成波导平衡混频器的设计实现

利用半模基片集成波导3 dB电桥设计了一种X波段单平衡混频器,并用印刷电路板工艺实现。首先设计并测试了半模基片集成波导电桥的性能,并给出测试结果。然后将半模基片集成波导电桥用于单平衡混频器的设计,并给出混频器的具体电路形式。该混频器具有良好的性能,与原有的基片集成波导电桥混频器相比体积更小、重量更轻。经测量混频器变频损耗小于8.6 dB,并在9 GHz～12 GHz频带内获得了比较好的响应平坦度。     

半模基片集成波导增益均衡器的设计和实现

针对增益均衡器小型化的发展趋势和要求,设计了多子结构单元级联的Ku波段的半模基片集成增益均衡器.谐振子单元与主传输线在三层介质基板上,成空间立体分布,构成七层结构;提出了利用多节微带线枝节进行阻抗匹配的过渡带设计方法,根据坐标变换分析得到HMSIW谐振腔的主模;采用羟基铁填充的吸收柱阵列调节衰减量和Q值,给出了该结构均衡器的设计步骤.与微带均衡器相比,该均衡器提高了Q值,减小了损耗.测试结果表明,该结构保持了和腔体类均衡器相同的性能,同时缩小了体积,实测结果与目标均衡曲线吻合度较好,最大差值为0.6dB.行波管与均衡器联测后,输出增益波动小于±0.4dB.     

Characterization of the Propagation Properties of the Half-Mode Substrate Integrated Waveguide

The propagation properties of the half-mode substrate integrated waveguide (HMSIW) are studied theoretically and experimentally in this paper. Two equivalent models of the HMSIW are introduced. With the first model, equations are derived to approximate the field distribution inside and outside the HMSIW. Using the second model, an approximate closed-form expression is deduced for calculating the equivalent width of an HMSIW that takes into account the effect of the fringing fields. The obtained design formulas are validated by simulations and experiments. Furthermore, the attenuation characteristics of the HMSIW are studied using the multiline method in the frequency range of 20–60 GHz. A numerical investigation is carried out to distinguish between the contributions of the conductive, dielectric, and radiation losses. As a validation, the measured attenuation constant of a fabricated HMSIW prototype is presented and compared with that of a microstrip (MS) line and a substrate integrated waveguide (SIW). The SIW is designed with the same cutoff frequency and fabricated on the same substrate as the HMSIW. The experimental results show that the HMSIW can be less lossy than the MS line and the SIW at frequencies above 40 GHz.      

基于Matlab的IIR数字滤波器设计方法比较及应用

滤波是信号处理的基础,滤波运算是信号处理中的基本运算,滤波器的设计也就相应成为数字信号处理的最基本问题之一。这里着重IIR数字滤波器的设计研究,应用Butterworth滤波器,ChebysheveⅠ型滤波器,ChebysheveⅡ型滤波器以及椭圆滤波器分别对低通、高通、带通和带阻四种滤波器形式进行比较仿真,通过不同设计方法的对比,将各种滤波器的设计特点很好地呈现出来。应用了Butterworth滤波器实现了混合信号频谱的分离,取得了良好的仿真效果。     

宽频带悬置线带通滤波器的研制

主要介绍了一种设计宽频带带通滤波器的新方法,即通过HFSS软件的本征模式求得悬置线交指滤波电路设计的初值,再经Designer软件建模优化,最终得到满足设计要求的滤波器电路。根据文中提供的设计方法,研制成功了通带分别为2～4GHz、4～8GHz、8～12GHz、12～18GHz的悬置线(SSS)带通滤波器,实测的滤波器响应曲线与仿真曲线吻合良好。该类滤波器电性能优良、成本低、体积小、易加工、易与微带电路集成,因而具有良好的应用前景。     

Applications of simulated annealing for the design of specialdigital filters

The authors describe the salient features of using a simulated annealing (SA) algorithm in the context of designing digital filters with coefficient values expressed as the sum of power of two. A procedure for linear phase digital filter design, using this algorithm, is presented and tested, yielding results as good as those for known optimal methods. The algorithm is then applied to the design of Nyquist filters, optimizing at the same time both frequency response and intersymbol interference, and to the design of cascade form finite-impulse-response (FIR) filters. The drawback of using SA is that the computation time is on the order of 1-2 h for each filter design, on the Sun 3/60. However, this was more than compensated by the versatility of the new algorithm, which can be used to design filters with multiple constraints     

基于新型宽带半模SIW巴伦的双平衡混频器

利用新型宽带半模基片集成波导(SIW)巴伦,设计制作了一个X波段双平衡混频器.利用SIW上下导带电流相位相差180°的原理,经优化设计使该巴伦具有体积小、带宽大、平衡性好等特点.测试结果表明,该双平衡混频器在8.7～9.7GHz的频率范围内变频损耗小于9dB,最小可达7.3dB;噪声系数小于10dB,实物面积为60mm×68mm.     

An Analytic Design Method for Microstrip Tunable Filters

This paper describes an analytic design procedure for microstrip tunable filters. Step-impedance resonators are employed and loaded with varactors for achieving agility in the filter response. Fixed lumped capacitors are utilized as admittance inverters in order to minimize the number of varactors in the filter. An analytic approach for filter design makes it possible to achieve a tunable filter showing the same frequency response when the center frequency is adjusted. A two-pole microstrip tunable filter whose center frequency can be adjusted from 1.1 to 1.5 GHz is designed to demonstrate the validity of design theory. A prototype tunable filter operating from 2.1 to 2.7 GHz is also designed and measured. A good agreement between the measured and simulated results is shown. Finally, three- and four-pole tunable filters are designed to show straightforward application of the presented design method to higher order tunable filter design.      

A State-Space Approach to Intermodulation Distortion Estimation in Fully Balanced Bandpass Gm– C Filters With Weak Nonlinearities

A state-space approach to estimating intermodulation distortion in bandpass G_m-C filters with fully balanced, weakly nonlinear transconductors is introduced. It results in compact analytic expressions applicable to G_m-C filters of any order. For verifying the theory, two G_m-C filters with fully balanced weakly nonlinear transconductors have been designed using Cadence. They have been simulated in SpectreS as well as modeled and simulated in Simulink. Theory and simulation results are found in good agreement     

Secondary LC filter analysis and design techniques forcurrent-mode-controlled converters

Small-signal characteristics of current-mode-controlled PWM converters with a second-stage LC filter are analyzed. It is shown that a secondary filter can be designed to provide good attenuation of the switching ripple while maintaining adequate stability margins with capacitive loading. The resonant frequencies and damping coefficients of the second filter are derived, and design guidelines are given. It is shown that the current-loop gain of the buck converter is not affected by the addition of the second-stage filters when a small filter inductance is used. Three design examples are presented to demonstrate the use of analysis results. Two filter examples are designed for a buck converter. One of the second filters shows the problems that arise with a poor design. A third example is the design of a second-stage filter for a buck-boost converter. In each of the design examples, the small-signal analysis was performed using EASY5 software and the circuits were simulated using the state-space simulation program COSMIR     

MOSFET-Only filter design automation based on polynomial regression with exemplary circuits

In this work, a novel design automation method is presented for easy construction of MOSFET-Only or MOSFET-C filters. In contrast to previous works in the literature, the proposed algorithm is simple since it uses polynomial fitting models obtained from SPICE data in order to reformulate small signal parameters and some DC characteristics of MOSFET’s. Polynomial regressive models facilitate to interact between design constraints (power, area, speed, pole frequency etc.) and design variables (operating voltages, currents and device dimensions). In this regard, two novel agile MOSFET-Only filters produced with the proposed automation process are presented in order to qualify the automation flow. The produced filters are simulated in LT-SPICE and CADENCE-SPECTRE environment by using 0.18 µm TSMC technology. These agile filters can easily be used in a wide range of applications such as encrypted communications or very high frequency circuits. In addition, it is shown that there is a good agreement between proposed design automation flow and simulations.     

Design of Millimeter-wave Rectangular Waveguide to HMSIW Transition Based on Trapezoidal-shaped Probe

In this letter, a compact rectangular waveguide-to-half mode substrate integrated waveguide (HMSIW) transition is presented. It uses a trapezoidal-shaped probe to couple the energy from rectangular waveguide to HMSIW. A back-to-back test module at Ka-band is fabricated and measured. It provides a return loss better than 15 dB and an insertion loss of 0.85 to 1.3 dB within a frequency range from 25 to 40 GHz. The circuit size of the proposed transition is reduced by approximately 81.8% as compared with the waveguide-to-HMSIW transition using antipodal fin-line. Additionally, no intermediate transition is needed for this transition, which simplify the design of transition circuit. The measurement results agree well with simulation results, which validate the feasibility of the transition. Also, a tolerance analysis is performed via the simulation to verify the reliability of this transition design.     

基片集成波导准感性窗滤波器的设计与实现

基于基片集成波导技术设计并用印刷电路板工艺实现了2种新型准感性窗滤波器,仿真和实验结果吻合良好。滤波器的中心频率为10.85GHz,相对带宽为4.6%,插损小于1.5dB,该滤波器具有平面集成和容易加工等优点。