一种基于图解的LCL滤波器设计和优化方法

相对L型滤波器,LCL型滤波器对高频谐波电流具有更好的衰减特性,更适合应用于大功率场合。但针对LCL型滤波器的参数设计也更复杂,不仅需要考虑滤波器对高频谐波电流的抑制效果,还需要考虑对控制器性能的影响。从LCL滤波器的数学模型入手,综合考虑滤波器的各个参数的限制条件,通过理论推导,直观地将滤波器各个参数对系统的影响用曲线表示在同一个平面中。通过图解分析,得到一种LCL滤波器的参数设计和优化的方法。最后给出一个单相并联型有源电力滤波器LCL滤波器的设计实例,并通过仿真和实验验证了设计方法的正确性和有效性。     

新型开环耦合谐振滤波器的设计与应用

为了满足日新月异的无线通信对小型化带通滤波器的要求,针对传统类型滤波器存在线性度、矩形系数、插入损耗、体积等方面的问题,笔者介绍了一种通过在微带开环谐振滤波器中引入交叉耦合,产生一对传输极点,从而提高滤波器选择性的滤波器设计方法,并讨论了这种滤波器的综合方法和实现流程。实际设计了一个六阶开环谐振滤波器,并给出了全波仿真结果。分析和仿真都表明这种滤波器具有体积紧凑、选择性高的优点。     

基于噪声源阻抗提取的EMI滤波器高效设计方法

针对传统EMI滤波器设计方法存在单次设计不准确、多次设计调试周期长的问题，提出一种基于噪声源阻抗提取的EMI滤波器高效设计新方法。首先通过插入无源二端口网络准确、迅速地获得噪声源阻抗幅值和相位；其次依据阻抗失配原则进行EMI滤波器拓扑选择；然后综合考虑噪声源阻抗、LISN端等效负载阻抗以及EMI滤波器高频分布参数对滤波器插入损耗的影响，令滤波器的理论插入损耗等于传导EMI测试频段范围内所需的插入损耗，得到滤波器各元件准确参数，实现了EMI滤波器精确设计。最后，通过一台LED驱动电源进行实验，结果表明一次设计即可满足预期效果，验证了所提方法的准确性和高效性。     

一种基于FTFN电流模式N阶高通滤波器的综合设计

提出了一种基于四端浮地零器(Four Terminal Floating Nullor,简称FTFN)的高阶电流模式滤波器综合设计方法。通过对n阶高阶电流模式滤波器传递函数进行分析,将其分解成用积分器实现的表达式,可实现高阶电流模式滤波器的综合。由该方法导出的滤波器所需元件较少,n阶滤波器仅需n个接地电容,外加n+1个FTFN和接地电阻,便于集成且与VLSI工艺兼容。给出了5阶巴特沃斯高通滤波器的设计实例,得出PSPICE仿真结果与理论分析相吻合,验证了该方法的可行性。     

分歧波导多工器综合方法研究

在卫星有效载荷系统中，多工器主要用于分离和合并射频信号，对整个系统性能具有实质性影响。分歧波导多工器以其性能佳、设计紧凑、易于工程实现等优点，在应用中十分常用。传统设计方法利用软件优化技术，优化波导枝节得到理想多工器响应，鲜有直接综合方法。介绍了一种负载为复阻抗的滤波器直接综合方法，并将其应用于分歧波导多工器综合设计。利用功率波归一化理论，计算滤波器网络端接复阻抗时的目标多项式，综合迭代各通道滤波器耦合矩阵，得到满足设计指标的多工器响应。以三工器为例列出综合步骤，最后通过仿真得到响应曲线，验证了方法的可行性。     

切比雪夫滤波器在动力蓄电池组检测中的应用

为了实现准确的动力蓄电池组综合性能测试,充放电电流纹波小(0.5%以下)是该测试系统一项基本要求.由于动力蓄电池组具有电压高、电流大、内阻极小,本身具有反电动势等特殊性,给滤波器的设计带来困难.动力蓄电池组属于低内阻的特殊性负载,其滤波器设计属于非匹配型滤波器设计,为了最大限度地减少非匹配型低通滤波器对直流电压固有的衰减,本文论述了动力蓄电池组综合性能测试系统的交流环节滤波器类型选取原则;并采用单端接载的综合设计方法计算滤波器的主要参数,以简化滤波器的设计;仿真及试验验证了该方法的可行性.     

APF输出滤波器的改进与优化设计

通过理论和仿真研究分析了LC型输出滤波器滤除高次谐波存在的不足,提出在LC型输出滤波器中串联一个小电阻的改进方法,改进后的输出滤波器能使混合型有源电力滤波(Hybrid Active Power Filter,简称HAPF)具有更好的性能.在此基础上,综合考虑滤波器的输出能力、滤波效果和动态性能,提出运用改进遗传算法设计输出滤波器,并对设计的实例进行实验.实验结果表明,采用改进遗传算法设计的输出滤波器使HAPF具有更好的整体性能.     

基于并行结构分布式算法的FIR滤波器设计

本文详细地叙述了线性相位FIR数字滤波器的一种设计方法。首先通过MATLAB设计出一个具体指标的FIR滤波器，并对滤波器系数进行了处理，使之便于在FPGA中实现。在滤波器硬件设计中，采用了分布式算法来计算滤波器中的乘积和运算，提高了信号的处理效率。Eh于采用了分布式算法的并行结构，提高了滤波速度。本论文用VHDL编写代码，用MaxplusⅡ进行编译、综合和仿真，FPGA器件选用ALTERA公司的FLEX10K系列7万门的芯片。最后，对设计结果做了验证，验证结果表明：这种方法大大减少了FPGA硬件资源的耗费，所设计的滤波器运算正确，实现了快速滤波功能。     

无源滤波器设计的优化方法及其仿真研究

利用混合罚函数的概念,将滤波、无功补偿以及电容电压电流等问题的解决方案的经济性综合为非线性规划问题,并讨论了滤波器设计的优化方法。中还建立了无源滤波器的综合友模型,从而大大简化了计算。通过仿真研究,进一步确认了该方法的正确性和可行性。     

综合电力滤波系统中无源滤波器的优化设计

本文首先介绍了由小容量有源滤波器和无源滤波器串联构成的综合电力滤波系统，继而对系统中无源滤波器的设计规则进行了分析，并采用时域的方法对无源滤波器进行了优化设计研究，以有效的减小有源滤波器的设计容量。     

Tunable optical nanocavity based on modulation of near-field coupling between subwavelength periodic nanostructures

We present the design and analysis of a tunable resonant optical filter based on modulation of the near-field coupling between two subwavelength periodic nanostructures embedded in a Fabry-Pe/spl acute/rot cavity. Due to the transverse localization of the optical field in the subwavelength gratings, their relative positioning strongly influences the near-field coupling between them and, thus, affects the resonance of the cavity. Rigorous electromagnetic analysis tools are applied to determine the optical characteristics of the filter with respect to the nanostructure lateral alignment, small variations in the shape of the nanostructures, and the physical separation of the nanostructures.     

Microwave filters with nonperiodic transmission characteristic

A microwave filter with nonuniform-coupled transmission lines is suggested. In contrast to known transmission-line microwave filters the transmission characteristic does not change periodically with frequency. The synthesis procedure shown reduces the design problem to the known synthesis of directional couplers with nonuniform coupling factor. A table of calculated coupling factor values of the microwave filter with an equi-ripple passband of 0.05 dB up to 1 dB and an equi-ripple stopband of 60 dB is given. A practical design example shows good agreement with theoretical results.     

A generalized Chebyshev channelizing filter

In this paper some issues concerning the design and implementation of a satellite transponder's channelizing filter of degree 6 are discussed. In particular, the construction of the transmission coefficient, the synthesis procedure and the realization are discussed. the amplitude and the group delay responses of the filter are optimized simultaneously to meet prescribed requirements. the prototype filter has been synthesized as a cross-coupled array. Explicit formulae for the element values in terms of the real and the imaginary parts of the poles of the transmission coefficient are derived. Single mode direct coupled cavity realization with positive and negative couplings has been developed. an experimental filter has been constructed, the measured responses are very close to the computed ones.     

General synthesis techniques for coupled resonator networks

This article presented general techniques for the synthesis and design of coupled resonator filters. The synthesis of the prototype circuit focuses on the compatibility between the coupling topology and the filtering function to be realized, providing some guidelines to select a proper coupling topology and to solve the coupling matrix synthesis problem. The dimensioning of the distributed filter is centered on parameter extraction techniques.     

Microwave filter design by synthesis and optimization

In this article, a process that might be described as "synthesis and approximation" was outlined. Starting from an exact prototype, the desired physical configuration using equivalent circuits and corrections to the resonators due to the influence of the coupling networks was approximated. A process that might be described as "approximation and optimization" was also outlined. Starting from an approximate filter network, optimization can be used to find an exact equal ripple solution. The starting point can be generated using synthesis or narrow-band approximations when appropriate. Applying optimization in an intelligent way allows the designer to circumvent some of the limitations of the classic ladder synthesis method. This article explores some ways to mix approximate filter dimensioning (based on network synthesis) and optimization (based on EM modeling), allowing a fast and accurate design of microwave filters     

EMI无源滤波器高频特性及其改善方法的研究

为了便于设计高性能的EMI滤波器,分析了滤波器寄生参数对其高频特性的影响.依据各元器件寄生参数的特点及其相互间的耦合关系,建立了差模滤波器的高频模型.在模型的基础上采取相应的屏蔽技术和合理的布局方案,尽量减小各元器件之间的耦合程度.采用电路网络等效法,消除了器件自身的寄生参数效应,并以此来改善滤波器的高频特性.从理论分析和实验结果来看,该方法对改善滤波器寄生参数的高频效应起了很大作用.因此该方法及其结论对EMI滤波器的设计有直接的指导意义.     

高阶椭圆滤波器的设计与仿真

分析信号频谱时为了提高系统的频率分辨率,需要设计性能优良的模拟滤波器.在所有的模拟滤波器中,椭圆滤波器有着极高的性能,但其传统设计方法过于复杂.本文介绍了椭圆滤波器VCVS(压控电压源)的结构,研究了一种通用的VCVS电路综合方法及元件值计算公式.利用MATLAB设计低通椭圆滤波器传递函数,成功综合出一款高性能七阶椭圆低通滤波器,EDA(电子设计自动化)软件OrCAD/PSpice10.5仿真和实际测试表明,其性能指标完全达到设计要求.     

New Current-mode all-pole and Elliptic Filters Employing Current Conveyors

New current-mode high-order all-pole and elliptic filters employing second-generation and third-generation current conveyors are presented in this paper. The synthesis method is based on signal flow graph design of simulating LC passive ladder filters. Simple architectures are obtained along with only grounded resistors and capacitors in our all-pole filter design. Moreover, the numbers of resistors, capacitors and current conveyors in our proposed all-pole filters are equal to the numbers of filter order. The proposed elliptic filter can be designed by only adding floating capacitor to the corresponding nodes as the all-pole filter counterpart. Third-order current-mode Chebychev and elliptic lowpass filters are demonstrated to verify the proposed method.     

新型混合型电力滤波器的研究

分析了新型混合型电力滤波器的补偿原理和补偿特性,给出了主电路各个组成部分的设计方法,及有源滤波器控制策略设计。利用MATLAB/Simulink构建了仿真模型,给出了仿真模型中电路的参数,得到了仿真结果。仿真结果表明,这种新型混合型电力滤波器可有效地改善无源滤波器或者单纯有源滤波器的滤波性能,这证明了设计方法的正确性。     

应用SBR/FDTD混合算法求解圆柱形复杂终端腔体RCS

在飞行器隐身设计中,为了实现进气道RCS的精确预估,提出了很多混合方法来提高计算精度和效率.本文给出了应用SBR/FDTD混合法分析带有复杂终端的圆柱型腔体的雷达散射截面问题的方法,重点分析了2种算法之间的耦合过程.最终通过对带有柱形终端的圆柱形腔体的计算和分析,并与文献结果进行对比,验证了该方法的正确性和有效性.