基于开关电容滤波器LTC1064的BPF设计

介绍了一种在2 kHz固定带宽条件下,中心频率可在0.5～100 kHz范围内调节的8阶椭圆带通滤波器的设计方法,采用2片LTC1064开关电容滤波器模块分别构成8阶椭圆高通和低通滤波器,然后两者级联构成带通滤波器,利用FPGA生成2路频率可控的时钟信号作为LTC1064的时钟输入,分别调节高通和低通滤波器的截止频率,从而实现带通滤波器的中心频率可调节,最后针对开关电容滤波器的直流偏移和时钟馈通问题进行后置滤波电路的设计.spice模型仿真结果表明,此带通滤波器的各项指标均达到了设计要求.     

基于设计空间的基本开关电容电路滤波器设计

提出了一种运用符号和数值计算与离散非线性优化相结合的滤波器设计方法——设计空间法,把滤波器的技术指标,即滤波器设计中要用到的一组参数映射到设计空间,并根据给定的准则寻找这一设计空间的最佳解决方案。然后介绍了一种新型的具有独立零点设置的基本二阶开关电容电路,最后通过实例阐述了用设计空间法设计一开关电容（SC）低通滤波器,实验证明了该方法的可行性,并且得到了预期的效果。     

电流模式八阶带通滤波器设计

本文提出了实现电流模式八阶带通滤波器的新方法,该法采用第二代改进式电流传送器构成的二阶电流模式带通滤波器作为基本积木块,得出了电流模式八阶带通滤波器的跳耦实现电路。该设计电路所有电阻,电容均接地,有利于电路集成化。     

高阶开关电容滤波器的设计和仿真

介绍了高阶开关电容滤波器以及二阶滤波器的排序和动态指定的基本原理和一般方法,根据预设的目标参数,借助Filtercad软件,对巴特沃兹型、切比雪夫型、以及椭圆形滤波器进行了仿真比较,得出椭圆形滤波器的频率响应比较理想,然后以6阶低通椭圆形开关电容滤波器为例,根据其传递函数,进行二阶滤波器的排序和动态指定,完成了电路的设计。该方法也适合高通、带通、带阻滤波器的设计。     

中压区域性动态电压恢复器的滤波器参数设计

动态电压补偿器(DVR)可治理配电网中的电压的跌落和不对称等动态电能质量问题,其输出滤波器的参数设计将影响电压跌落的补偿效果。本文对应用于中压配电网的级联H桥DVR的输出滤波器参数的设计进行了研究。通过对逆变器输出电压在电容两端和电感两端分配的情况进行分析,推导了滤波器电感和电容取值与电感两端和电容两端电压分配之间的关系,并结合低通滤波器谐振频率与DVR等效开关频率和系统工频的关系,计算得到电容和电感的取值。结合实例给出了具体的实现步骤,通过仿真计算验证了文中提出的滤波器参数设计方法的正确性和有效性。     

低通滤波器在串联型电力有源滤波器中的应用

分析了低通滤波器用于串联型电力有源滤波器时的特殊性，建立了分频段仿真的电路模型并且提出了分频段设计方法。利用该方法，为一台15kW样机设计的低通滤波器取得了较为满意的结果。为进一步消除开关纹波提出了在低通滤波器中引入陷波滤波器的改进方法。仿真和实验结果表明，加了陷波滤波器后，低通滤波器的滤波特性得到了很大改善。陷波滤波器的设计方法在文中也作了介绍。     

一种新型截止频率可调的滤波器设计

从传统短截线低通滤波器的设计理论出发,推导出新型开关滤波器谐振单元的截止频率和插入损耗计算公式.以频率响应的变化规律为依据,将不同谐振单元级联通过改变并联枝节长度设计任意截止频率的低通滤波器.最后利用PIN管的开关特性,连接不同微带枝节从而改变谐振网络的枝节长度,实现不同截止频率开关滤波器的设计.在同一电路设计了截止频率分别为0.9 GHz、1.5 GHz、2 GHz三波段的低通滤波器,并对其进行了仿真、优化和加工实物测试,验证了理论分析的正确性.     

贴片电容在滤波器中的应用

一般采用电阻、电容构成积分形式的低通滤波器,它可以为单阶或多阶滤波器。它的通频带由电阻、电容参数决定,截止速度取决于其阶数。低通滤波器简称为LF。它是滤波器的一种,具有很多分类:有一阶滤波器、二阶滤波器、高阶滤波器;无源滤波器、有源滤波器;射频滤波、本振滤波、中频滤波、低通滤波;LC滤波器、陶瓷滤波器、声表面滤波器、晶体滤波器等,如图1所示。     

基于等效电路模型映射的DGS低通滤波器设计

在分析缺陷地结构(DGS)单元及其等效电路模型的基础上,采用了一种新颖的椭圆DGS单元并建立了椭圆DGS单元与其等效电路之间的映射关系。根据该映射关系利用电磁仿真的S参数提取出等效电路模型的元件值,通过基于矩量法(MoM)的快速电路仿真优化得到目标频率响应对应的电路元件值,根据电路优化的结果调谐低通滤波器的电磁模型。最终获得所需低通滤波器结构。实验证明该滤波器的电磁仿真、等效电路仿真及实测结果吻合,验证了该设计方法的有效性和准确性。     

含开关电容的有源箝位多电平逆变器

针对传统多电平逆变器输出电平不易扩展的问题,结合开关电容能输出二倍电容电压的特点,提出一种含开关电容的有源箝位多电平拓扑。该拓扑能明显增加输出电平数,由开关电容带来的冗余状态也有利于电容电压均衡,且所含电容少逆变器体积小,适用于低压高功率密度的场合。分析了新拓扑中基本单元分别为开关电容单元和飞跨电容单元的情况,从电容容值和成本角度出发,得出了含开关电容的有源箝位型多电平拓扑构成原则。在此基础上从开关管数量、电容数量和冗余开关状态数量3个方面对比了新拓扑与普通有源中点箝位型拓扑的特性,最后以九电平组合拓扑为例,分析其工作原理、调制策略及电容电压控制策略。仿真和实验结果验证了其可行性。     

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.     

A novel lowpass to bandpass transformed PI control strategy for series hybrid active power filter

In this paper, simulation and experimental based evaluation of novel lowpass to bandpass transformed PI control strategy for series hybrid active power filter is presented. In the series hybrid topology, the active filter is in series with a capacitor and this whole arrangement comes in parallel with an inductor. This hybrid setup is introduced in series between the source and load. The control structure is derived in the stationary reference frame through lowpass to bandpass transformation of ordinary PI controller transfer function. The effect of controller on system performance as well as its selective harmonic elimination is illustrated. The modelling, simulation and experimental results are presented.     

A family of modular fully differential witched capacitor filters for simulating ladder filters

The switched capacitor filters proposed in this paper are based on the simulation of LC ladder filters through the state variable equations. They include all-pole and finite transmission zero, lowpass filters, bandpass and highpass filters. the introduced family of filters has a fully differential structure; consequently it has the advantages of improved power supply and common mode rejection ratios and extended dynamic range. Since the proposed family of filters simulates LC ladder filters, it inherits their low passband sensitivities. One of the main advantages of this family of filters is that it has a modular structure composed of key and auxiliary circuits. This modular structure results in easier design and implementation procedures in VLSI fabrication. the double-sampling concept is applied to the introduced modular blocks, which is essentially needed in high-frequency applications. A comparison with similar published work available in the literature is presented and illustrative examples are given.     

Design of wave-sc filters using building blocks

Besides switched-capacitor (SC) filters developed for high volume production, e.g. the PCM-codec lowpass filter, numerous low volume applications exist in the area of solid-state filtering. to open up this application field for SC filters, a novel wave-SC filter structure is presented. the filter design using this concept requires only moderate design and layout skills since only a limited library of highly modular building blocks is required. It is also suitable for analogue gate array applications. As will be shown, the wave equations which are known from the theory of wave digital filters can be realized using stray-insensitive SC integrators and SC amplifiers only. Exemplary designs of a lowpass, a highpass, and a bandpass filter will be carried out with the building blocks presented. the theoretical results are verified by measurements at the breadboarded lowpass filter.     

精密程控低通滤波器

本文简述了ＭＦ１０开关电容滤波器的工作原理。介绍了利用ＭＦ１０组成滤波器品质因数和外接电阻的计算方法。最后给出了一个程控四阶巴特沃思低通滤波器的实用电路及测试结果。     

基于改进型Butterworth传递函数的高阶低通滤波器的有源设计

基于改进型Butterworth传递函数,提出了一种设计高阶低通滤波电路的方法.推导出奇数高阶低通滤波电路是1个一阶Butterworth低通滤波电路和若干个二阶滤波网络的级联,偶数高阶低通滤波电路是若干个二阶滤波网络的级联,给出设计高阶低通滤波电路元件参数的计算公式,利用这些公式可简单快速地设计出满足技术要求的任意高阶低通滤波电路.     

Direct synthesis techniques for general Chebyshev filters: lowpass,highpass, and bandstop cases

Conventional synthesis techniques for general Chebyshev lowpass, highpass, and bandstop filters are usually based on general Chebyshev filtering function, from which lowpass prototype is set up. By applying the lowpass to lowpass, highpass, or bandstop frequency transformation on realization networks of lowpass prototypes, final realization networks of general Chebyshev lowpass, highpass, and bandstop filters are obtained. In this paper, direct synthesis techniques for general Chebyshev lowpass, highpass, and bandstop filters are discussed. Transmission zeros can be placed wherever they are desired to control the performance of the filters. Unlike conventional synthesis techniques, they derive filtering polynomials constituting network parameters directly in the lowpass, highpass, or bandstop domain, which might find applications in analogue and digital filter design. Several examples are presented for demonstration. Copyright © 2015 John Wiley & Sons, Ltd.     

新型谐振式混合有源滤波器的研究

为减小有源滤波器的容量,提出了一种新型混合有源滤波器的拓扑结构。其基本思想是:根据分流原理,适当控制有源部分来等效增大系统支路的谐波阻抗,提高无源滤波器的滤波效果;将有源部分与基波谐振电路并联来减小有源部分容量;合理地配置注入支路的参数,以保证滤波器具有较好的滤波能力和一定的无功补偿能力。仿真和实验结果证明了所提出的混合有源滤波器的可行性和正确性,所提出的拓扑结构消耗的有效材料少,体积小,占地面积小。     

Explicit design formulae for wideband bandpass filters

A new design technique is developed for the realization of wideband bandpass filters synthesized in the form of a lowpass filter cascaded with a highpass filter. For the maximally flat and chebyshev response cases, approximate explicit design formulae are provided to allow a direct design technique to be used. Results obtained by using this design technique agree with those obtained by direct synthesis and offer a significant improvement over the direct lowpass—highpass cascade obtained by frequency scaling.