共查询到20条相似文献,搜索用时 203 毫秒
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设计IIR数字滤波器的遗传优化算法 总被引:2,自引:0,他引:2
提出了IIR数字滤波器设计的遗传优化法。这是一种模拟自然遗传和达尔文进化理论的随机并行优化算法。首先,详细描述了遗传算法并给出了计算步骤,然后将遗传算法用于IIR数字滤波器的优化设计,最后给出了模拟计算结果。 相似文献
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设计ⅡR数字滤波器的遗传优化算法 总被引:7,自引:1,他引:6
提出了ⅡR数字滤波器设计的遗传优化法。这是一种模拟自然遗传和达尔文进化理论的随机并行优化算法。首先,详细描述了遗传算法并给出了计算步骤,然后将遗传算法用于ⅡR数字滤波器的优化设计,最后给出了模拟计算结果。 相似文献
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阵列天线方向图综合作为智能天线的一项重要技术对于复杂系统的优化问题提出了更高的要求.本文结合差分进化的基本思想和遗传算法的基因交叉和变异方法构建了一种新的混合优化方法.该算法使用差分进化算子作为主要优化手段,结合遗传算法优胜劣汰的基本思想以及其中的交叉和变异方法,通过融合两种优化方法各自的优点,可以显著改善多参数、高度非线性问题的优化结果、提高计算效率.计算机仿真结果表明,与现有算法相比,该算法用于天线方向图综合具有收敛速度快、优化能力强、算法可靠等优势. 相似文献
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声表面波滤波器的匹配电路设计 总被引:1,自引:0,他引:1
介绍了通过测试仪器采集的声表面波(SAW)滤波器的Sij(i,j=1,2)参数来优化匹配电路的方法。首先将采集的Sij(i,j=1,2)参数转换为SAW滤波器Yij(i,j=1,2)参数,然后建立新的S12(或S21)参数与匹配电路的依赖关系,通过优化匹配电路元件值,而使滤波器的插入损耗和通带波动满足目标值,该方法的主要优点是考虑整个通带特性,而不是考虑通带内的某一点(如中心频率)。 相似文献
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从模拟滤波器到数字滤波器的转换以及寻找滤波器参数的最优解是IIR参数滤波器用于扬声器频响实时补偿的两个关键问题。本文提出一种根据模拟滤波器的中心频率、增益和品质因数来自适应选择S域到Z域转换方法,通过扬声器频响曲线的实时包络来划分峰谷,给出了一种滤波器参数的优化方法,提升了数字滤波器与模拟原型的匹配度,从而减少滤波器个数、加速了滤波器的优化计算。实验结果表明,所提出的方法使补偿滤波器的个数和总时间开销比现有的补偿方法分别减少了大约43%和55%。 相似文献
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一种新的基于极大似然估计的系统辨识方法 总被引:1,自引:0,他引:1
进化计算是一种基于自然选择和自然变异机制的并行随机优化算法。由于递推极大似然估计法难以实现性能指标函数的全局寻优,所以本文提出了将改进的进化计算用于系统参数辨识的方法。计算机仿真结果表明,该算法能够实现似然函数的全局寻优。 相似文献
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图像滤波的形态学开、闭型神经网络算法 总被引:2,自引:0,他引:2
该文设计完成了一种具有实用意义的形态学开、闭滤波的神经网络模型及其滤波参数的优化训练算法。实验结果表明该方法设计简便,实用性强且易于推广,对提高形态滤波性能效果明显。分析表明,形态滤波器可分解为形态滤波运算和结构元素选择两个基本问题。形态滤波运算规则已由定义本身确定,于是形态滤波器的最终滤波性能就仅仅取决于结构元素的选择。进行自适应优化训练的目的正是使结构元素具有图像目标的形态结构特征,从而使形态滤波器对复杂变化的图像具有良好的滤波性能和稳健的适应能力。 相似文献
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Digital filters with adjustable frequency domain characteristics are referred to as variable digital filters. Variable filters are useful in the applications where the filter characteristics are required to be changeable during the course of signal processing. Especially in real time applications, variable filters are needed to change their coefficients instantaneously such that the real time signal processing can be performed. The present paper proposes a very efficient technique for variable 1D digital filter design. Generally speaking, the variable coefficients of variable digital filters are multidimensional functions of a set of spectral parameters which define the desired frequency domain characteristics. The authors first sample the given variable 1D magnitude specification and use the samples to construct a multidimensional array, then propose an outer product expansion method for expanding the multidimensional array as the sum of outer products of 1D arrays (vectors). Based on the outer product expansion, one can reduce the difficult problem of designing a variable 1D digital filter to the easy one that only needs constant 1D filter designs and 1D polynomial approximations. The technique can obtain variable 1D filters having arbitrary desired magnitude characteristics with a high design accuracy 相似文献
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《Microwave Theory and Techniques》1968,16(3):142-147
The coaxial low-pass filters described are of the conventional stepped impedance type consisting of a cascade of alternating low and high impedance sections of line. Exact prototype filters having Chebyshev equal-ripple characteristics are obtained from published tables giving the characteristic impedances of the sections. The capacitive discontinuities at the junctions are compensated by a new method which is exact at the cutoff frequency, and nearly exact in the region of this frequency. The production of low-pass filters with a passband VSWR of 1.05 or less is feasible and experimental results are described for such designs. 相似文献
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A. V. Zakharov M. E. Il’chenko I. V. Trubarov 《Journal of Communications Technology and Electronics》2017,62(2):185-193
New designs of planar three-resonator bandpass filters with cross coupling having a large variety of frequency characteristics are considered. In addition to better one-sided selectivity, such filters implement symmetric amplitude–frequency characteristics with an attenuation pole at each side of the passband. These filters can also have constant delay time in the passband. Concatenation of the proposed three-resonator filters leads to multiresonator filters with high selectivity determined by two attenuation poles at each side of the passband. It is found that the type of connection of the middle resonator in the circuit of a three-resonator filter with cross coupling results in substantial differences in amplitude–frequency characteristics. The results of modeling of different frequency characteristics are presented. It is shown that filters have small dimensions, which are comparable to overall dimensions of microwave ceramic filters. For example, dimensions of a three-resonator stripline filter designed for a frequency of 1.9 GHz are 9.4 × 5 × 2 mm for the permittivity of the filter material εr = 92 and dimensions of a six-resonator filter are 10 × 9.4 × 2 mm. 相似文献
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The bilinear z-transformation has been used by various authors (Golden and Kaiser 1964, Broomer 1966) to design recursive digital filters. The necessity to select an equivalent. continuous filter makes this method very laborious. Remes exchange algorithm has also been used in the design of recursive filters (Remes 1957, Deczky 1974) but not will the same success as for the design of non-recursive filters (McClennan and Parks 1973. Holt et al. 1975 ) due to its dependence on the initial conditions on optimization methods. In this paper we-present a design technique, based on Remes second exchange algorithm. This provides a versatile approximation method for the design of a wide range of minimax-type digital recursive filters. Furthermore, the method is extended to the design of continuous filters using suitable mapping methods. In the examples given, filters arc designed with various frequency characteristics for the pass band and the stop band and also with predefined zeros in the stop band. 相似文献
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《Microwave Theory and Techniques》1963,11(3):162-178
Direct-coupled resonator filters in transmission line are discussed. The resonators consist of sections of transmission line coupled either by series capacitances or shunt inductances. Over narrow frequency bands, such filters show characteristics similar to those of lumped-constant filters and their design is straightforward. The design of direct-coupled resonator filters over wide (as well as narrow) frequency bands is presented here using the quarter-wave transformer as a prototype circuit. Several numerical examples (with fractional bandwidths between 10 per cent and 85 per cent) are worked out to illustrate the method. It is shown that the response can be improved by optimizing the line impedances. 相似文献
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Design and Implementation of Linear Phase FIR Filters for Biological Signal Processing 总被引:1,自引:0,他引:1
This paper presents a new method for designing digital linear phase, finite impulse response filters with loose frequency response characteristics, but with good time resolution as is required in biological signal conditioning. The design is very simple and has been used with success in the microcomputer implementation of filters for the automated processing of electroencephalographic (EEG) data. Examples and a discussion of possible filter implementations are included. 相似文献
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The authors present a technique to design two-channel filter banks in three dimensions where the sampling is on the FCO (face centred orthorhombic) lattice, The ideal 3-D sub-band is of the truncated octahedron shape. The design technique is based transformation of variable method equivalent to the generalised McClellan transformation. The filters are FIR, have linear phase and achieve perfect reconstruction. Although the sub-band shape is quite complicated, the ideal frequency characteristics are well approximated. This is illustrated with an example. The technique provides the flexibility of controlling the frequency characteristics of the filters with ease. The filters can be implemented quite efficiently due to the highly symmetrical nature of the coefficients of the transformation. The authors also modify and extend the basic design technique to impose the zero property (the number of zeros of the filter transfer function at the aliasing frequency) on the sub-band filters. This property is important when the filter bank is used iteratively in a tree-structured manner as a discrete wavelet transform system and the issue of regularity arises. Several design examples are presented to illustrate the design technique 相似文献