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1.
The construction of nomographs for transitional classical filters is described. Gain functions of classical filters are related to filter requirements resulting in a formulation for the general gain nomograph. The transitional filters that are products of approximating polynomials are incorporated into the general gain nomograph resulting in transitional filter nomographs that are sums of the individual nomographs. Nomographs for transitional filters using alternative forms where poles are interpolated are also considered. The resulting nomographs allow for quick optimization of transitional filter frequency response in many cases. Design examples are submitted and discussed. The proposed transitional filter nomographs provide the engineer with increased insight into the selection of classical transitional filters with optimum frequency response. 相似文献
2.
最少OTA元件的电控有源多功能滤波器 总被引：1，自引：0，他引：1
由有源RC状态变量滤波器导出了一个新的OTA有源滤波器.该电路可在单一结构的不同端点上同时获得低通、带通和高通滤波功能,且具有很好的电调谐能力.该电路具有低g_m参数变化灵敏度,此外,电路只需要四个OTA元件,这是实现KHN电路所需要的最少元件数. 相似文献
3.
Mohd Amin Malik 《Journal of The Franklin Institute》2010,347(2):523-532
A new configuration realizing current/voltage-mode (CM/VM) universal filter using two four terminal floating nullors (FTFN) and four passive components is presented. The current-mode configuration has single input and three outputs and realises simultaneously lowpass (LP), bandpass (BP) and highpass (HP) responses from which allpass (AP) and notch functions can also be implemented. The voltage-mode filter has three inputs and two outputs and can be configured to realise all the five filtering functions. The circuit in current-mode uses grounded capacitors which are ideal for monolithic integration. Besides using a bare minimum number of passive components, the topology enjoys low active and passive sensitivity figures. Experimental and PSPICE simulation results are also included. 相似文献
4.
提出了用改进式电流传送器实现二阶电流模式状态变量滤波器新电路，并由此得到了高通、带通、低通滤波特性。计算机仿真结果表明理论分析是正确的，所提电路具有灵敏度甚低的特点。 相似文献
5.
提出了一种具有独立输出端口的电流传送器二阶电流模滤波器的新电路，并由此得到了高通、带通和低通滤波特性．该电路具有敏感度较低和ＲＣ元件数较少的特点 相似文献
6.
M.A. Sid-Ahmed 《Journal of The Franklin Institute》1983,316(6):467-476
A method is presented, that can be readily written in a computer program, to obtain the closed-form solution of the impulse response of a digital filter. The extension of this approach to two-dimensional digital filters and to analog filter transfer functions is also presented. Examples are shown. 相似文献
7.
Statistical sensitivity measures for gain and phase functions of high Q active networks are studied. Explicit formulas for the sensitivity measures of second-order active RC networks are presented. The formulas obtained are shown to be simple and can be readily calculated for various high Q active RC filters. General formulation of the sensitivity measure for multiple-loop feedback active networks, which use high Q biquadratic active RC networks, is also given. 相似文献
8.
A new active R filter which realizes a second order bandpass transfer function is given. The network employs only resistors and two operational amplifiers. Sensitivities to all passive and active circuit components are very low. Design equations are given and experimental results are also included. 相似文献
9.
Several techniques are available for implementing a scalar digital filter using lattice and ladder structures which are known to yield low noise realizations. Of these, the lattice and ladder structures proposed by Gray and Markel have the advantage of being internally scaled. Block implementation of a scalar digital filter offers a number of advantages. In this paper, new algorithms to realize block digital filters in the form of cascaded lattice or ladder two-pairs are proposed. Block lattice and ladder structures similar to Gray and Markel's scalar structure are obtained by using Levinson recursion. Also, normalized block lattice and ladder structures are developed. 相似文献
10.
Explicit expressions of transfer functions for digital tan filters with low-pass, high-pass, band-pass, and band-stop characteristics approximating given design specifications are advanced. The higher order transfer function satisfying the design specification is expressed as the product of first-order and second-order filter sections of identical forms but with different coefficient values. All coefficients of these low-order filter sections are expressed in explicit forms related simply to the specification values. Thus, the result developed can be easily applied for the cascade or time-sharing realization. The low-order filter section developed here can be implemented with the fewest multipliers.The design formulae for Butterworth, Chebyshev, inverse Chebyshev and elliptic approximations are included. The transfer functions for all these filters are expressed in the same form of low-order filter section with different coefficient values. 相似文献
11.
基于提升小波的SAR图像斑点噪声抑制方法 总被引：1，自引：0，他引：1
斑点噪声去除是对合成孔径雷达(synthetic aperture radar,SAR)图像自动分割、分类、目标检测和其它定量专题信息提取处理前必要的步骤。首先简要回顾了各种传统的SAR图像斑点噪声去除方法。在充分考虑SAR图像斑点噪声乘性特征的基础上,对SAR图像进行对数变换,将乘性噪声转变为加性噪声,然后再对图像进行提升小波分解,采用Bayes Shrink阈值对小波系数进行处理。最后根据4个指标来对比不同方法的去噪效果。结果表明,与传统的滤波方法相比,基于提升小波的去噪方法在图像均匀区域的辐射特性保持和斑点噪声抑制能力方面具有较大的优势。与传统小波相比,提升小波不但在运算速度上有优势,而且省内存。 相似文献
12.
A new transitional filter based on the sum of filter polynomials is proposed and discussed. It shall be shown that the approach allows for greater flexibility in adjusting passband and stopband gain shapes. The sensitivity of the filter transfer function is analyzed and related to the approximation problem. Some new modified classical filters are also derived including maximally flat (Butterworth) and equiripple (Chebyshev) types. Several examples of combining Butterworth, Chebyshev and sync-tuned filters are presented and compared to those obtained using the conventional product method. The new transitional filter provides an alternative to other forms and provides a means for isolating the effects of non-uniformly distributed pole angles. 相似文献
13.
Active-R filters are designed using internally compensated operational amplifiers (OA) and resistors only. A one-pole or 6 dB roll off model for the PA's is assumed in these designs. This model is adequate for active-RC filters. However, for active-R filters such an assumption leads to serious accuracy as well as stability problems, thereby limiting the highest operating frequency of these filters to well below their potential maximum. It is shown in this article that a two-pole or 12 dB roll off model more accurately reflects the behaviour of the OA's for the above active-R realizations. A quantitative measure of the limitation imposed by this model on such realizations is also presented. Extensive computer simulation and experimental tests have been carried out that verify closely the theoretical predictions. 相似文献
14.
基于传输函数的信号流图模拟,一种新的具有最少元件 Ｏ Ｔ Ａ电容滤波器结构被提出⒚任何种类任何阶电压传输函数均可由该结构实现,设计公式简单⒚文中设计了各种二阶滤波器,分析了这种实现的电压传输函数的灵敏度,给出了三阶椭圆低通滤波器设计实例及计算机仿真结果⒚ 相似文献
15.
提出了采用单四端浮点零器实现电流模式二阶全通／陷波和一阶全通滤波器新电路,该电路具有高输出阻抗和氏无源灵敏度特点。 相似文献
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17.
An analytical technique is developed for designing multidimensional (M-D) separable-denominator recursive digital filters that meet, simultaneously, magnitude and phase specifications. A cubic symmetry that exists in the M-D frequency response is incorporated into the M-D filter structure. The denominator and the numerator of an M-D transfer function are designed separately. The former is used to approximate constant group delays and the latter is used to adjust an overall magnitude response. The filter is analytically designed by solving linear equations only. This serves to reduce the amount of calculations drastically. The stability of the resulting filter is always guaranteed. Finally, two examples are given to illustrate the utility of the proposed technique. 相似文献
18.
This paper proposes a new wave digital filter derived from doubly terminated LC-ladder networks by replacing each series or shunt arm element of the ladder by its equivalent digital two-port. It is shown that such two-ports may be cascaded without the use of adapters defined by Fettweis (1). A number of realizations of the wave digital two-ports, which are canonic with respect to both multipliers and delays, have been obtained. Also a realization which is canonic with respect to multipliers only is given and an example considered using this realization. The sensitivity of this filter with respect to the multiplier coefficient changes due to finite word length is compared with the conventional cascaded digital filter and also the one proposed by Renner and Gupta. It is found that the proposed filter appears to be a more desirable form of implementation than the conventional cascade form and comparable to that of Renner and Gupta (2). 相似文献
19.
提出了一种电流模式多功能滤波结构。这种结构仅使用５个ＣＣ器件，３个接地电阻和两个接地电容。选择三具输出端中的一个或它们的组合即可实现五种基本的二阶滤波功能，元件灵敏度很低。比Ｓｅｎａｎｉ提出的结构简单。 相似文献
20.
现代CMOS工艺的发展使得在CMOS工艺上设计射频IC前端成为可能。但在传统CMOS工艺集成的片上螺旋电感品质因数(Q)偏低,大大影响其性能。通过引入负电导实现螺旋电感Q值提升,并将其应用于共栅低噪声放大器的设计。 相似文献