Showing papers on "Prototype filter published in 1980"
TL;DR: In this paper, approximate design formulas for bandpass filters using parallel coupled stripling stepped impedance resonators (SIR) are derived, taking into account the arbitrary coupling length as well as quarter-wavelength coupling.
Abstract: Approximate design formulas for bandpass filters using parallel coupled stripling stepped impedance resonators (SIR) are derived. The formulas take into account the arbitrary coupling length as well as quarter-wavelength coupling. Some advantages of this filter are its abilities to control spurious response and insertion loss by changing the structure of the resonator. Using the design formulas two experimental filters were designed and fabricated and their performances closely matched design data.
784 citations
09 Apr 1980
TL;DR: This paper discusses a family of filters that have been designed for Quadrature Mirror Filter (QMF) Banks that provide a significant improvement over conventional optimal equiripple and window designs when used in QMF banks.
Abstract: This paper discusses a family of filters that have been designed for Quadrature Mirror Filter (QMF) Banks. These filters provide a significant improvement over conventional optimal equiripple and window designs when used in QMF banks. The performance criterion for these filters differ from those usually used for filter design in a way which makes the usual filter design techniques difficult to apply. Two filters are actually designed simultaneously, with constraints on the stop band rejection, transition band width, and pass and transition band performance of the QMF filter structure made from those filters. Unlike most filter design problems, the behavior of the transition band is constrained, which places unusual requirements on the design algorithm. The requirement that the overall passband behavior of the QMF bank be constrained (which is a function of the passband and stop band behavior of the filter) also places very unusual requirements on the filter design. The filters were designed using a Hooke and Jeaves optimization routine with a Hanning window prototype. Theoretical results suggest that exactly flat frequency designs cannot be created for filter lengths greater than 2, however, using the discussed procedure, one can obtain QMF banks with as little as ±.0015dB ripple in their frequency response. Due to the nature of QMF filter applications, a small set of filters can be derived which will fit most applications.
724 citations
TL;DR: In this paper, a frequency domain implementation of the LMS adaptive transversal filter is proposed, which requires less computation than the conventional LMS filter when the filter length equals or exceeds 64 sample points.
Abstract: A frequency domain implementation of the LMS adaptive transversal filter is proposed. This fast LMS (FLMS) adaptive filter requires less computation than the conventional LMS adaptive filter when the filter length equals or exceeds 64 sample points.
350 citations
TL;DR: Discusses the effects of finite operational-amplifier gain and bandwidth on the response of the most widely used switched-capacitor filter section.
Abstract: Discusses the effects of finite operational-amplifier gain and bandwidth on the response of the most widely used switched-capacitor filter section. Formulas are derived for the minimum acceptable values of the DC amplifier gain and the unity-gain frequency under specified conditions.
111 citations
TL;DR: In this paper, the theoretical considerations as well as practical circuits which are useful to the designer attempting to implement high-speed filters are presented, and the theoretical and practical circuits are discussed.
Abstract: Monolithic filters using switched-capacitor techniques are beginning to be used in commercial audio frequency communication circuits [1], [2], [10]. The fact that these filters are MOS compatible, high precision and low power makes them very attractive in these filter applications. The usefulness of switched-capacitor filters will be greatly increased if the frequency range of these filters can be extended above the voice band. The purpose of this paper is to present the theoretical considerations as well as practical circuits which are useful to the designer attempting to implement high-speed filters.
103 citations
Book•
29 Apr 1980
TL;DR: A concise introduction to digital filtering, filter design and applications in the form of Kalman and Wiener filters, and the graphic method for frequency response computations, FIR filter design by the frequency sampling technique, equiripple FIRfilter design, circular convolution and an introduction to multirate digital filters.
Abstract: A concise introduction to digital filtering, filter design and applications in the form of Kalman and Wiener filters. Each subject is developed gradually with the help of worked examples. Covers both the theory of digital filters and their use in extracting information from noisy data. New to this edition: the graphic method for frequency response computations, FIR filter design by the frequency sampling technique, equiripple FIR filter design, circular convolution and an introduction to multirate digital filters.
66 citations
TL;DR: In this paper, energy and power analogies are used for the analysis of cascaded (possibly time-varying) lattice digital filters, leading to the requirements for passivity of the sections, and a procedure for the removal of zero-input parasitic oscillations, along with several other results.
Abstract: Energy and power analogies are used for the analysis of cascaded (possibly time-varying) lattice digital filters. This approach leads to the requirements for passivity of the sections, and a procedure for the removal of zero-input parasitic oscillations, along with several other results.
65 citations
TL;DR: A synthesis method is presented for the class of low-pass prototype filters having an equiripple passband response with a single transmission zero at infinity and the remainder at a finite real frequency.
Abstract: A synthesis method is presented for the class of low-pass prototype filters having an equiripple passband response with a single transmission zero at infinity and the remainder at a finite real frequency. To synthesize the network, the even mode or the odd mode is obtained directly using the alternating pole technique and little accuracy is lost for networks up to degree 19. Tables of element values for commonly used specifications are included. Finally, the practical advantages of this prototype when used to design certain classes of filters are discussed.
63 citations
TL;DR: In this paper, simple approximate design equations are derived for an even degree (n /spl ges/ 6) low-pass inverter capacitance prototype filter having single transmission zeros at both real and imaginary frecuencies.
Abstract: Simple approximate design equations are derived in this paper for an even degree (n /spl ges/ 6) low-pass inverter capacitance prototype filter having single transmission zeros at both real and imaginary frecuencies. This is achieved by utilizing one or two additional couplings. The transmission zeros improve considerably the passband group delay and increase the skirt selectivity compared to those of the ordinary Chebyshev prototype. An exact and more complicated method based on the known generalized Chebyshev rational function approximation is also presented for the comparison. The prototype with one additional coupling is utilized to realize narrow-bandpass printed circuit filters consisting of half-wave resonators.
58 citations
TL;DR: In this article, the authors describe a number of simple (first-, second-, or third-order) switched-capacitor circuits, which can be used as simple self-contained filters, or as filter sections in the cascade realization of a higher order transfer function.
Abstract: This paper describes a number of simple (first-, second-, or third-order) switched-capacitor circuits. These can be used as simple self-contained filters, or as filter sections in the cascade realization of a higher order transfer function. All these sections are free from parasitic effects, and all can be designed directly in the sampled-signal domain. Low-pass, high-pass, bandpass, and all-pass circuits are discussed, with and without finite nonzero transmission zeros.
58 citations
TL;DR: In this article, a delta modulation-like sampled analog filter structure for realizing low-pass filters is described, which uses only the coefficients 0, + 1, and -1 and can be fabricated as a programmable CCD filter.
Abstract: A delta modulation-like sampled analog filter structure for realizing low-pass filters is described. The filter uses only the coefficients 0, + 1 , and -1 and can be fabricated as a programmable CCD filter. Interpolation and decimation are employed to increase the accuracy of the delta modulation. It is shown that with this scheme a given response can be realized arbitrarily closely. Examples are included.
TL;DR: In this article, switched-capacitor decimation and interpolation circuits are described, where the decimator can function as an input stage, the interpolator as an output stage in a filter system.
Abstract: Novel switched-capacitor decimation and interpolation circuits are described. The decimator can function as an input stage, the interpolator as an output stage in a filter system. This allows the use of differing clock rates in the various stages of the system, which in turn can result in simpler antialiasing requirements, more practical element values and lower sensitivities for the individual filters in the system.
TL;DR: In this paper, three bandpass filters were constructed for use with a 0.3K bolometer and the center frequencies and bandwidths of the filters were chosen to correspond with the 1, 2 and 3 mm atmospheric windows.
TL;DR: In this paper, a natural generalization is presented which allows the method to be used to design arbitrary zero-phase 2-D FIR filters, and the decoupling of the design problem into one-dimensional and two-dimensional components.
Abstract: The design of 2-D FIR zero-phase filters by transformations is a popular and well-developed technique, but it suffers from the disadvantage that in its current form only filters with four-quadrant symmetry can be designed. In this contribution a natural generalization is presented which allows the method to be used to design arbitrary zero-phase 2-D FIR filters. This generalization preserves the two most important features of the method-the decoupling of the design problem into one-dimensional and two-dimensional components, and the existence of an efficient structure for realizing the filter.
TL;DR: In this paper, a switched-capacitor filter design technique based on the LDI transformation is presented, which uses a novel floating inductance simulation circuit to preserve the maximum power transfer property.
Abstract: A switched-capacitor filter design technique based on the LDI transformation is presented which uses a novel floating inductance simulation circuit. By choosing the filter terminations properly, the circuits are shown to preserve the maximum power transfer property. A low-pass filter design example is presented to illustrate the low-sensitivity property of this technique.
TL;DR: In this paper, a general technique for realizing Bruton's LDI transformation in low-pass switched-capacitor ladder filters is presented, which results is switched capacacitor integrators that are insensitive to parasitic capacitances.
Abstract: A general technique for realizing Bruton's LDI transformation in low-pass switched-capacitor ladder filters is presented, which results is switched-capacitor integrators that are insensitive to parasitic capacitances. It is shown that the correct filter response may be obtained by realizing only the stable poles of the LDI transformed LC network. Realization of these "stable" poles is reduced to the problem of solving a system of nonlinear equations. The design of a third-order Chebyshev low-pass filter is presented as an example.
TL;DR: In this article, an optimal recursive digital filter design algorithm is presented to meet simultaneous specifications of magnitude and group delay responses, which is the unconstrained least pth optimization method for a constrained nonlinear programming problem.
Abstract: This paper presents a new optimal recursive digital filter design algorithm to meet simultaneous specifications of magnitude and group delay responses. The technique used is the unconstrained least pth optimization method for a constrained nonlinear programming problem. An illustrative example shows the drastic reduction of group delay ripple in comparison with the all-pass equalizer method.
TL;DR: In this paper, three classes of digital-filter structures, namely two classes of cascade structures and one class of wave structures, are compared with regards to the number of arithmetic operations, the inherent speed capability, the output noise due to product quantization, and the sensitivity to multiplier-coefficient quantization.
Abstract: Three classes of digital-filter structures, namely two classes of cascade structures and one class of wave structures, are compared with regards to the number of arithmetic operations, the inherent speed capability, the output noise due to product quantization, and the sensitivity to multiplier-coefficient quantization Four types of filters are considered, namely a Butterworth low-pass filter, a Chebyshev high-pass filter, an elliptic bandstop filter, and an elliptic band-pass filter The arithmetic is assumed to be of the fixed-point type, numbers are assumed to be in two's complement representation, and number quantization is assumed to be by rounding
TL;DR: In this paper, a general formula for the filter function of maximally flat f.i.r. digital filters using modified Krawtchouk polynomials is presented.
Abstract: A general formula for the filter function of maximally flat f.i.r. digital filters using modified Krawtchouk polynomials is presented. This formula permits a direct calculation of the filter weights. It is especially advantageous for either high or low passband/stopband width ratios.
01 Dec 1980
TL;DR: Four independent real-time programmable switched-capacitor filters have been fabricated on a single NMOS chip and includes permanent programming capability as well as an on-chip oscillator.
Abstract: Four independent real-time programmable switched-capacitor filters have been fabricated on a single NMOS chip. The filters are second-order sections with digitally programmable Q and center frequency. Either low-pass or bandpass functions are available by selecting the appropriate input. The device is microprocessor compatible and includes permanent programming capability as well as an on-chip oscillator. The circuit implementation, programming capability, and operation are described.
TL;DR: In this article, the authors consider the design of linear-phase FIR digital filters with finitely precise coefficients and derive a bound on the attainable stopband attenuation, and also develop techniques for designing FIR filters with fine-grained coefficients.
Abstract: The FIR (finite impulse response) filter is an essential tool for a large number of applications in communication. In this paper we consider the design of linear-phase FIR digital filters with finitely precise coefficients. Coefficient inaccuracy is known to degrade the frequency response of band-select FIR filters, especially in the stopband region. We derive a bound on the attainable stopband attenuation, and we also develop techniques for designing FIR filters with finitely precise coefficients. Mixed-integer programming algorithms are presented to select finitely precise coefficients for a filter that best approximates an arbitrary magnitude characteristic in the minimax sense. Our method generates a number of possible solutions including that of simple rounding or truncation and then selects the best finitely precise coefficients from this set. In this way, significant improvement in the filter performance is gained over methods that simply round or truncate the infinitely precise coefficients. We also show how integer programming can be used to design filters with powers of two coefficients. Such filters are easier to mechanize since they do not require multipliers.
TL;DR: A new, simplified method is presented for the design of group-delay filters that permits the realization of filters that are equal ripple approximations to the smooth portions of given group- delay characteristics.
Abstract: A new, simplified method is presented for the design of group-delay filters. The method is derived assuming that the filter order is large and that the filter group-delay function is smooth. Satisfactory results, however, are achieved even if both of these assumptions do not apply. The method permits the realization of filters that are equal ripple approximations to the smooth portions of given group-delay characteristics. The filters are constructed from second-order all-pass sections in cascade. Examples of linear group-delay, quadratic group-delay, and "stair step" group-delay filters are presented. The design method is simple enough to be implemented with dedicated hardware.
TL;DR: It is shown that the noise generated in a passive first-order switched-capacitor lowpass filter has its origin in the thermal noise of the m.o.s. transistors' on-resistance.
Abstract: It is shown that the noise generated in a passive first-order switched-capacitor lowpass filter has its origin in the thermal noise of the m.o.s. transistors' on-resistance. The spectral description of this noise at the output of the filter is given. The measurements made on a discrete laboratory model show good correspondence with the analytical results and confirm the noise model established.
TL;DR: In this article, it was shown that the digital lattice filter utilized as a predictor in speech processing is a special case of a broad class of filters with identical properties in which the delay element is replaced by an arbitrary analog or digital all-pass filter.
Abstract: It is shown that the digital lattice filter utilized as a predictor in speech processing is a special case of a broad class of filters with identical properties in which the delay element is replaced by an arbitrary analog or digital all-pass filter. The performance of three filters in this class, the delay element and single-pole analog and digital all-pass sections, are compared for the special estimation application.
TL;DR: An iterative optimization technique, based on a Modified Marquardt algorithm, is proposed for the design of asymmetric 2-D half-plane recursive digital filters with a zero-phase implementation.
Abstract: An iterative optimization technique, based on a Modified Marquardt algorithm, is proposed for the design of asymmetric 2-D half-plane recursive digital filters with a zero-phase implementation. To illustrate the technique a fan-filter and a circular lowpass filter were designed. The technique can also be used for the design of quarter-plane filters.
01 Jan 1980
TL;DR: The charge domain filter appears to retain the intrinsic CCD shift register advantages, while overcoming many of the disadvantages of the present CCD transversal filter architecture.
Abstract: A new charge-transfer device architecture has been developed for implementing recursive filters in the minority charge domain. A three pole filter using this architecture has been designed and fabricated. The measured filter characteristics are in close agreement with theoretical predictions to approximately 0.2 percent. The charge domain filter appears to retain the intrinsic CCD shift register advantages (e.g. high-speed, small output capacitance, wide linear dynamic range), while overcoming many of the disadvantages of the present CCD transversal filter architecture.
TL;DR: The possibility of simplifying high-order state-space active filters having minimized sensitivities while maintaining good sensitivity behavior, by slightly altering the systems about their optimized values is examined.
Abstract: This paper investigates the use of the similarity tranformation in the generation of high-order state-space active filters having minimized sensitivities. A sensitivity performance measure similar to the Rosenblum-Ghausi multiparameter sensitivity figure is defined, and a frequency independent relationship between the sensitivity measures of equivalent systems is derived. The results of optimizing an all-pole bandpass filter and a low-pass elliptic filter are presented, along with a detailed analysis of some of the attributes of the optimized realizations. The paper then examines the possibility of simplifying these optimized systems while maintaining good sensitivity behavior, by slightly altering the systems about their optimized values.
09 Apr 1980
TL;DR: A class of digital Finite Impulse Response filters for decimation ( sampling rate decrease) and interpolation (sampling rate increase) are presented, making them an economical alternative to conventional implementations for certain applications.
Abstract: A class of digital Finite Impulse Response (FIR) filters for decimation (sampling rate decrease) and interpolation (sampling rate increase) are presented. They require no multipliers and limited storage, thus making them an economical alternative to conventional implementations for certain applications. A digital filter in this class consists of cascaded ideal integrator stages operating at a high sampling rate and an equal number of comb stages operating at a low sampling rate. Together, a single integrator-comb pair produces a uniform FIR. The number of cascaded integrator-comb pairs is chosen to meet design requirements for stopband attenuation, passband falloff and transition width.
DOI•
01 Sep 1980TL;DR: A system of bandpass filters, modelled on the early mechanisms of human vision, is described which provides a simple means to eliminate blur and noise from an image.
Abstract: A system of bandpass filters, modelled on the early mechanisms of human vision, is described which provides a simple means to eliminate blur and noise from an image. The system automatically adjusts itself to suit local signal conditions in an image, without prior knowledge of signal statistics.
TL;DR: In this article, a new type of wide field-of-view filter is proposed and analyzed, which consists of a multilayer stack of two dielectric media such that the dispersion curves of these two media intersect at a particular wavelength.