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1.
Fei Xiao 《International Journal of Circuit Theory and Applications》2016,44(3):584-601
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. 相似文献
2.
Fei Xiao 《International Journal of Circuit Theory and Applications》2016,44(8):1514-1532
Recently, direct synthesis techniques (DSTs) have been presented for filter synthesis. Unlike conventional synthesis techniques, DSTs derive the filtering polynomials of the filters to be synthesized directly in their own frequency domain. These filtering polynomials are real coefficient so that they might find applications in various fields. Furthermore, DSTs might be used to customize filters with a more complex frequency response, such as asymmetric frequency response or multi‐band frequency response. In this paper, DSTs are compared with some well‐known filter synthesis techniques. Then, the application of DSTs in the design of lumped‐element LC filters, distributed‐element filters, active RC filters, and infinite impulse response digital filters with complex frequency response is discussed. Some examples are presented for demonstration. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
3.
Fei Xiao 《International Journal of Circuit Theory and Applications》2018,46(3):415-426
In radio frequency/microwave or even higher frequency range, various transmission‐line filters have been proposed for frequency selection. Specifically, there is a kind of transmission‐line filters not having source/load inverters. To design them is somewhat difficult, if their physical mechanism is not fully understood. In this paper, the concept of the distributed‐ to lumped‐element equivalence is applied in the synthesis of several microstrip band‐pass filters without source/load inverters. As demonstrated, it can help to reveal the physical mechanism of the filters such as how the resonances are created and coupled. In addition, the distributed‐ to lumped‐element equivalence relations between filter specifications and structural parameters are presented and good initial dimensions are calculated, which will facilitate filter design. Several examples are presented for demonstration. 相似文献
4.
Fei Xiao Huarong Gong Yong Zhang 《International Journal of Circuit Theory and Applications》2018,46(10):1827-1837
To design microstrip filters is not easy for the sake of their distributed‐element effect. Undoubtedly, to understand their physical mechanism is very important to their design. In this paper, one effective approach to design some third‐order microstrip bandpass filters with each of 2 transmission zeros at each side of the passband is discussed. Lumped‐element equivalent circuits are used to represent these microstrip filters. Then, these lumped‐element equivalent circuits can be synthesized by direct synthesis technique we recently proposed, so that it is likely to calculate initial structural parameters of these microstrip filters and then facilitate their design. Verified by the measured results of the filter designed through the approach in this paper, the performance of the filters is close to ideal frequency responses. Furthermore, another third‐order microstrip bandpass filter is presented, in which open‐circuited stubs at input/output ports are introduced to suppress one specified harmonic to improve out‐of‐band attenuation. 相似文献
5.
《International Journal of Circuit Theory and Applications》2017,45(1):3-17
In this paper, the synthesis of inverse general Chebyshev bandpass filters is discussed. Unlike general Chebyshev filters that flexibly place transmission zeros to mainly control the performance of the filters in the stopband and keep constant ripple in the passband, inverse general Chebyshev filters are featured by flexible placement of reflection zeros in the passband and keep constant ripple in the stopband. Two approaches to directly derive filtering polynomials of inverse general Chebyshev bandpass filters in the bandpass domain are discussed in detail. By applying the zero‐extraction method, these filtering polynomials could be realized through appropriate networks. Finally, two examples are presented for demonstration. 相似文献
6.
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. 相似文献
7.
交叉耦合腔体滤波器的设计与实现 总被引：3，自引：1，他引：3
通过对广义Chebyshev滤波器设计方法的深入研究,改进了由技术指标提取滤波器阶数和传输零点的综合方法;基于提出的分析模型,用Ansoft HFSS建立同轴腔体滤波器,对谐振腔的本征频率、耦合系数、抽头位置进行仿真计算。通过960MHz交叉耦合滤波器实例设计验证了该综合方法的有效性。 相似文献
8.
S. C. Dutta Roy 《International Journal of Circuit Theory and Applications》2010,38(5):543-549
Simple modifications are proposed for the normal as well as the inverse Chebyshev filter (ICF) for facilitating doubly terminated LC ladder realization, and consequently cascaded active‐RC implementations, for all specifications. The resulting filters are compared with two recently proposed solutions, as well as the competing conventional ones in terms of cutoff slope and the Q of the complex poles. The advantages of the modified filters are discussed. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
9.
介绍了一种并联混合型有源电力滤波器(HAPF)的方法,阐述了HAPF的基本工作原理,着重分析了有源电力滤波器谐波抑制的控制策略,给出了复合控制技术的数学模型.这种策略综合了检测负载谐波电流控制方式和检测电网谐波电流控制方式的优点.实践证明,提出的HAPF及控制方法滤波效果好,动态性能高. 相似文献
10.
Fei Xiao 《International Journal of Circuit Theory and Applications》2019,47(1):133-151
A power divider is ideally a lossless reciprocal device performing vector summation of two or more input signals, which is an extremely important circuit component in wireless communication systems or radar systems. In this paper, a general concept of lumped-element power divider is discussed. Then, a semi-analytical synthesis technique is presented. General odd-mode and even-mode analysis method is proposed for multi-port symmetrical network and applied in the analysis of N-way lumped-element power dividers. The transmission networks and the matching networks can be synthesized step by step, which greatly simplify their analysis. The transmission networks can be synthesized by those well-known synthesis techniques for two-port networks, and thus the transmission property of power dividers can be accurately controlled. The matching networks are determined by optimization to ensure certain isolation between the output ports. The design procedure is simple and accurate. Apart from the capability of power division, power dividers are also able to play the role of impedance transform and signal processing. Some examples of power dividers with filtering capability are presented for demonstration. In this paper, a general concept of lumped-element power divider is discussed. Then, a semi-analytical synthesis technique is presented. General odd-mode and even-mode analysis method is proposed for multi-port symmetrical network and applied in the analysis of N-way lumped-element power dividers. Transmission networks and matching networks can be synthesized step by step, which greatly simplify their analysis. Apart from the capability of power division, power dividers are also able to play the role of impedance transform and signal processing. 相似文献
11.
分歧波导多工器综合方法研究 总被引：1，自引：0，他引：1
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。 相似文献
12.
Michael Z. Q. Chen Kai Wang Minghui Yin Chanying Li Zhiqiang Zuo Guanrong Chen 《International Journal of Circuit Theory and Applications》2015,43(4):427-437
This paper is concerned with the realizability problem of n‐port resistive networks that contain 2n terminals. A necessary and sufficient condition for any real symmetric matrix to be realizable as the admittance of an n‐port resistive network containing 2n terminals is obtained. This condition is based on the existence of a parameter matrix. Furthermore, the values of the elements are expressed in terms of the entries of the admittance matrix and the parameter matrix. Finally, a numerical example is used to illustrate the results. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
13.
本文在实Banach空间中研究了几种边界条件:LSB—条件、LS—条件、BP—条件、CR—条件和弱向内条件之间的关系.我们的结果改进了Williamson[1]中的结果.同时,举了一些反例说明定理中条件的必要性及条件之间的强弱关系. 相似文献
14.
针对高性能的模拟电能质量干扰发生器价格昂贵,难以在普通实验室普及使用的情况,本文基于直接信号合成技术设计了一种模拟电能质量干扰发生器。采用直接频率合成芯片AD9850产生正弦波信号,经椭圆无源低通滤波后进入电能质量波形形成电路;利用单片机控制数模转换芯片DAC7811与电子开关CD4053B,实现暂时过电压、电压短时跌落、电压短时中断以及电压凹陷等功能;利用放大器LM617对信号进行一次放大,通过高压高速集成功率运放PA89A进行二次放大,采用并联三极管扩流技术增大系统输出电流。通过样机试验,该设计能够模拟多种电能质量信号波形,相对经济,能实现大功率。 相似文献
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为提高目前基于掩蔽与基于频谱映射的语音增强方法性能上界以及复杂环境下的泛化能力,提出了一种在联合复频谱与复掩蔽学习框架下的协作式单通道语音增强方法。 该方法采用编码器-双分支解码器结构,在编解码部分设计了一种交互协作学习单元(ICU)来监督交互语音信息流,并提供有效的潜在特征空间;中间层则是设计出一种多尺度融合 Transformer,以少量参数在空间-通道维度上多尺度地提取细节信息后融合输出,同时对语音子频带与全频带信息建模。 在大、小数据集与 115种噪声环境下进行实验,结果表明该方法仅以 0. 57 M 的参数量,取得比大部分先进且相关方法更优的主、客观指标,具有良好的鲁棒性与有效性。 相似文献
17.
The recently reported Pascal approximation with non‐equiripple magnitude response leads to transfer functions of order equal or comparable to that of the Chebyshev approximation, offering an alternative to the equiripple Chebyshev approximation. Both approximations can be used in passive filter design and have similar design limitations when the order turns out to be even. In this paper, these design issues are thoroughly addressed, and the exact conditions are set under which even‐order passive Chebyshev and Pascal filters cannot be directly synthesised and either the order has to be increased to the next odd integer value or the modified filter must be designed. Pascal approximation is used for the first time for the design of doubly resistively terminated passive LC filters, and it is shown that the even‐order design issue is much less restricting making Pascal superior to Chebyshev filters in that even‐order filters can be directly designed to meet specifications that cannot be met by Chebyshev filters of the same even order. The theoretical results are confirmed through several design examples. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
18.
为实现在单相电网电压畸变条件下车网互联(V2G)系统的灵活直接功率控制,首先将复矢量引入电网谐波条件下的单相瞬时功率计算,分析了电网电压畸变时的单相有功功率与无功功率的成分。在建立单相V2G系统复矢量信号模型的基础上,设计复数控制器实现了功率稳定与并网电流谐波抑制2个独立目标的控制,并采取功率前馈控制改善了系统动态性能。最后,搭建了3.5 k V·A单相V2G系统的MATLAB/Simulink仿真模型与实验系统,仿真与实验结果验证了理论分析的正确性以及所提控制方案的有效性。 相似文献
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Renzo Perfetti 《International Journal of Circuit Theory and Applications》2012,40(3):307-312
In this letter, it is shown how the canonical circuits for the synthesis of symmetrical two‐port networks can be derived from the eigendecomposition of the impedance matrix. Extensions to reciprocal two‐port networks are discussed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献