Showing papers on "Prototype filter published in 1967"
Book•
15 Jan 1967
TL;DR: In this article, the authors present the theory of effective PARAMETERS in terms of the effectiveness of different types of filters in the real-time domain and the effect of different filters on the performance of the network.
Abstract: CHAPTER 1 FILTERS IN ELECTRONICS 11 Types of Filters 12 Filter Applications 13 All-Pass Filters 14 Properties of Lattice Filters 15 Filter Building Blocks 16 Higher Order Filters 17 Coil-Saving Bandpass Filters 18 Frequency Range of Applications 19 Physical Elements of the Filter 110 Active Bandpass Filters 111 RC Passive and Active Filters 112 Microwave Filters 113 Parametric Filters CHAPTER 2 THEORY OF EFFECTIVE PARAMETERS 21 Power Balance 22 Types of General Network Equations 23 Effective Attenuation 24 Reflective (Echo) Attenuation 25 Transmission Function as a Function of Frequency Parameter, s 26 Polynomials of Transmission and Filtering Functions 27 Filter Networks 28 Voltage and Current Sources 29 The Function D (s) As An Approximation Function 210 Example of Transmission Function Approximation 211 Simplest Polynomial Filters in Algebraic Form 212 Introduction to Image=Parameter Theory 213 Bridge Networks 214 Examples of Realization in the Bridge Form 215 Hurwitz Polynomial 216 The Smallest Realizabel Networks, 217 Fourth-Order Networks 218 Fifth-Order Networks CHAPTER 3 FILTER CHARACTERISTICS IN THE FREQUENCY DOMAIN 31 Amplitude Responses 32 Phase-and Group-Delay Responses 33 Group Delay of an Idealized Filter 34 Group Delay-Attenuation Relationship 35 The Chebyshev Family of Response Characteristics 36 Gaussian Family of Response Characteristics 37 A Filter with Transitional Magnitude Characteristics 38 Legendre Filters 39 Minimum-Loss Characteristics 310 Synchronously Tuned Filters 311 Arithmetically Symmetrical Bandpass Filters 312 Attenuation Characteristics of Image Parameter Filters 313 Other Types of Filter Characteristics 314 Plots of the Attenuation and Group Delay Characteristics CHAPTER 4 ELLIPTIC FUNCTION AND ELEMENTS OF REALIZATION 41 Double Periodic Elliptic Functions 42 Mapping of s-Plane into u-Plane 43 First Basic Transformation of Elliptic Functions 44 Filtering Function in z-Plane 45 Graphical Representation of Parameters 46 Characteristic Value of D(s) 47 An Example of Filter Design 48 Consideration of Losses 49 Introduction of Losses by Frequency Transformation 410 Highpass Filters with Losses 411 Transmission Functions with Losses 412 Conclusions on Consideration of Losses 413 Realization Process 414 Bandpass Filter with a Minimum Number of Inductors 415 The Elements of a Coil-Saving Network 416 Consideration of Losses in Zig-Zag Filters 417 Realization Procedure 418 Numerical Example of Realization 419 Full and Partial Removal for a Fifth-Order Filter CHAPTER 5 THE CATALOG OF NORMALIZED LOWPASS FILTERS 51 Introduction to the Catalog 52 Real Part of the Driving Point Impedance 53 Lowpass Filter Design 54 Design of Highpass Filters 55 Design of LC Bandpass Filters 56 Design of Narrowband Crystal Filters 57 Design of Bandstop Filters 58 Catalog of Normalized Lowpass Models CHAPTER 6 DESIGN TECHNIQUES FOR POLYNOMIAL FILTERS 61 Introduction to Tables of Normalized Element Values 62 Lowpass Design Examples 63 Bandpass Filter Design 64 Concept of Coupling 65 Coupled Resonators 66 Second-Order Bandpass Filter 67 Design with Tables of Predistorted k and q Parameters 68 Design Examples using Tables of k and q Values 69 Tables of Lowpass Element Values 610 Tables of 3-dB Down k and q Values CHAPTER 7 FILTER CHARACTERISTICS IN THE TIME DOMAIN 71 Introduction to Transient Characteristics 72 Time and Frequency Domains 73 Information Contained in the Impulse Response 74 Step Response 75 Impulse Response of an Ideal Gaussian Filter 76 Residue Determination 77 Numerical Example 78 Practical Steps on the Inverse Transformation 79 Inverse Transform of Rational Spectral Functions 710 Numerical Example 711 Estimation Theory 712 Transient Response in Highpass and Bandpass Filters 713 The Exact Calculation of Transient Phenomena for Highpass Systems 714 Estimate of Transient Responses in Narrowband Filters 715 The Exact Transient Calculation in Narrowband Systems 716 Group Delay Versus Transient Response 717 Computer Determination of Filter Impulse Response 718 Transient Response Curves CHAPTER 8 CRYSTAL FILTERS 81 Introduction 82 Crystal Structure 83 Theory of Piezoelectricity 84 Properties of Piezoelectric Quartz Crystals 85 Classification of Crystal Filters 86 Bridge Filters 87 Limitation of Bridge Crystal Filters 88 Spurious Response 89 Circuit Analysis of a Simple Filter 810 Element Values in Image-Parameter Formulation 811 Ladder Filters 812 Effective Attenuation of Simple Filters 813 Effective Attenuation of Ladder Networks 814 Ladder Versus Bridge Filters 815 Practical Differential Transformer for Crystal Filters 816 Design of Narrowband Filters with the Aid or Lowpass Model 817 Synthesis of Ladder Single Sideband Filters 818 The Synthesis of Intermediate Bandpass Filters 819 Example of Band-Reject Filter 820 Ladder Filters with Large Bandwidth CHAPTER 9 HELICAL FILTERS 91 Introduction 92 Helical Resonators 93 Filter with Helical Resonators 94 Alignment of Helical Filters 95 Examples of Helical Filtering CHAPTER 10 NETWORK TRANSFORMATIONS 10 1 Two-Terminal Network Transformations 102 Delta-Star Transformation 103 Use of Transformer in Filter Realization 104 Norton's Transformation 105 Applications of Mutual Inductive Coupling 106 The Realization of LC Filters with Crystal Resonators 107 Negative and Positive Capacitor Tranformation 108 Bartlett's Bisection Theorem 109 Cauer's Equivalence 1010 Canonic Bandpass Structures 1011 Bandpass Ladder Filters Having a Cononical Number of Inductors without Mutual Coupling 1012 Impedance and Admittance Inverters 1013 Source and Load Transformation Bibliography Index
777 citations
TL;DR: Capacitive grids are used to construct effective low-pass filters for the far infrared and sub-millimeter wave region as discussed by the authors, which are closely related to optical interference filters and to microwave filters of the lris-coupled resonator type.
98 citations
TL;DR: There are several classes of optical bandpass filters which use optical tunneling: the Fabry-Perot filter, the single Tunnel layer filter, and the multiple tunnel layer filter.
Abstract: Several applications of optical tunneling (frustrated total reflection) are briefly discussed. There are several classes of optical bandpass filters which use optical tunneling: the Fabry-Perot filter (alias the FTR filter), the single tunnel layer filter, and the multiple tunnel layer filter. The properties of these filters are examined. The multiple tunnel layer filter shows promise as an ir long-wave pass filter.
46 citations
TL;DR: In this paper, transformations to convert lowpass systems to highpass, bandpass and band-elimination systems in the case of pulse transfer functions of digital filters are given.
Abstract: Transformations to convert lowpass systems to highpass, bandpass and band-elimination systems in the case of pulse transfer functions of digital filters are given in this paper. It is believed that these results, for z plane transformations, are the first ones to be published in this field.
32 citations
TL;DR: In this article, an exact method is presented to find transmission factors of transmission line filters which approximate a constant delay in a maximally flat sense, where the class of filters considered is a doubly loaded arbitrary cascade of transmission lines and open- or short-circuited stubs in series or in shunt, all elements being of equal length and nondispersive.
Abstract: An exact method is presented to find transmission factors of transmission line filters which approximate a constant delay in a maximally flat sense. The class of filters considered is a doubly loaded arbitrary cascade of transmission lines and open- or short-circuited stubs in series or in shunt, all elements being of equal length and nondispersive. This includes a variety of transmission line filters: \lambda/4 transformers, distributed lowpass filters, stub filters of various configurations, interdigital filters, etc. Explicit expressions, valid for any order n of the filter, are derived for the normalized transmission factor, and for its squared magnitude, and its phase on the imaginary axis. In addition, a table and design curves are provided for the cases n = 2, 3, 4 , and 5 and an example is given to demonstrate their use.
29 citations
TL;DR: The development of economic hybrid integrated filter building blocks is reported on, based on a metliod of network synthesis that generates general second-order networks by pole-zero cancellation of passive RC and active all-purpose frequency emphasizing networks.
Abstract: The development of economic hybrid integrated filter building blocks is reported on. The units are versatile and can be utilized for a wide variety of applications. They are based on a metliod of network synthesis that generates general second-order networks by pole-zero cancellation of passive RC and active all-purpose frequency emphasizing networks.
22 citations
TL;DR: In this paper, adaptive tracking filter application to stabilization of structural bending modes of SI-B launch vehicle is proposed to stabilize the structural bending mode of the launch vehicle during the launch.
Abstract: Simulation results of adaptive tracking filter application to stabilization of structural bending modes of SI-B launch vehicle
11 citations
TL;DR: In this article, an inductorless 16-20 kHz bandpass filter has been built to test the hypothesis that low-sensitivity filters can be constructed if all the inductors in an LC filter are replaced by their gyrator-capacitor equivalents.
Abstract: An inductorless 16–20 kHz bandpass filter has been built to test the hypothesis that low-sensitivity inductorless filters can be constructed if all the inductors in an LC filter are replaced by their gyrator-capacitor equivalents. The measured results show that this filter has low component sensitivity and excellent temperature stability and can be constructed from moderate-tolerance components.
10 citations
TL;DR: In this paper, the distortion of recorded spectral lines by a variety of noise filters is discussed and the effectiveness of noise suppression by the filters is compared on a noise-equivalent basis.
9 citations
TL;DR: In this paper, a novel type of bandpass filter constructed in ferrite-loaded waveguide and using the evanescent-mode principle of operation is described. But their performance is limited to 3-section bandpass filters.
Abstract: A description is given of a novel type of bandpass filter constructed in ferrite-loaded waveguide and using the evanescent-mode principle of operation. These filters may be multisection, and their operating band of frequencies may be tuned by a single-knob control of the d.c. magnetic field on the ferrite. Performance of a 3-section bandpass filter is given.
9 citations
TL;DR: Examination of response curves shows why the nearly critical‐damping time characteristics of Bessel designs are preferred compared to the underdamped, although relatively constant, magnitude response of Butterworth and elliptic designs.
Abstract: Design optimization procedures for vocoder bandpass filters have evolved as a result of successful digital computer simulations of voice‐excited vocoders and spectrum channel vocoders. These procedures yield designs that result in improved performance of the channel vocoder. The procedures, implemented by computer programs, permit choosing the proper response characteristics for the various bandpass and low‐pass filters required in a channel vocoder. Examination of response curves shows why the nearly critical‐damping time characteristics of Bessel designs are preferred compared to the underdamped, although relatively constant, magnitude response of Butterworth and elliptic designs. In addition to impulse response, consideration is also given to: (a) Filter spectral‐resolving power (i.e., passband and attenuation‐band characteristics); and (b) filter magnitude‐phase characteristics at the frequency crossover point of contiguous filters. For vocoder designs employing unequal bandwidth filters, channel characteristics may be preserved either by using higher‐order filters for the wider frequency bands or by combining an appropriate number of narrow‐band equal‐bandwidth filters in parallel. Attention to magnitude‐phase characteristics requires evaluation of resultant gain at different crossover frequencies when two filters are combined in parallel. This evaluation is performed for filters combined with and without phase inversion and leads to a choice of a proper bandwidth scale factor. Such evaluation also shows why vocoder performance can sometimes be improved by shifting the phase of alternate channels by 180°.
05 Jul 1967
TL;DR: Low pass filter, bandpass filter, and design of input system for speech recognition computer was discussed in this paper, where a low pass filter was used for low-frequency speech recognition.
Abstract: Low pass filter, bandpass filter, and design of input system for speech recognition computer
TL;DR: In this article, several techniques for achieving non-reciprocity in YIG filters employing stripline or miniature coaxial line construction are presented, where the circuit element possesses isolator and circulator properties as well as that of a ferrimagnetic filter.
Abstract: Several techniques for achieving nonreciprocity in YIG filters employing stripline or miniature coaxial line construction are presented. Nonreciprocal filters can be designed with either single-ended or double-ended nonreciprocity. In either case, the circuit element possesses isolator and circulator properties as well as that of a ferrimagnetic filter. Experimental results have indicated that nonreciprocity greater than 10 dB over octave bandwidths is possible with passband characteristics similar to those of conventional YIG filters. The insertion loss may be somewhat higher than the latter, depending on the technique of nonreciprocity utilized. Nonreciprocal YIG filters are useful with TWT microwave receiver systems as preselectors and post-selectors and obviate the need for isolators. These filters are also useful as tunable microwave circulators in conjunction with tunnel diode amplifiers and parametric amplifiers. An individual filter may be used as a diplexer, while several filters will provide multiplexer operation.
TL;DR: In this paper, an active filter network is described which is almost independent of element changes, and the analysis shows that the constant of the negative impedance converter may be changed by as much as ±10% without appreciably influencing the properties of the filter.
Abstract: The active element has the greatest influence on the properties of active filters and may cause oscillations especially in more complicated networks. An active filter network is described which is almost independent of element changes. The analysis shows that the constant of the negative impedance converter may be changed by as much as ±10% without appreciably influencing the properties of the filter. Synthesis was carried out for a whole system of filters of fourth- and sixth-degree with various minimum attenuations in the stop-band. The changes of all other elements are briefly considered and it is shown that the influence of all elements not determining the position of the transmission zero is less than the same relative change of the impedance converter constant.
TL;DR: In this paper, a simple alternative approach to the conventional method for the synthesis of digital Chebychev filters is outlined, and it is shown that synthesis of Chebyschev digital filters may be performed in the zplane, without referring to continuous filters.
Abstract: A simple alternative approach to the conventional method for the synthesis of digital Chebychev filters is outlined. Conventionally, digital filters are obtained by transforming Continuous filters. It is shown that synthesis of Cheby?chev digital filters may be performed in the zplane, without referring to continuous filters.
TL;DR: In this paper, a new class of time-varying lowpass and high-pass filters is described in which the stopband attenuation is obtained by outphasing in a quadrature-modulation arrangement, the undesired associated frequency translation or inversion being cancelled by a suitably chosen second step of quad rature demodulation or both.
Abstract: A new class of time-varying lowpass and highpass filters is described in which the stopband attenuation is obtained by outphasing in a quadrature-modulation arrangement, the undesired associated frequency translation or inversion being cancelled by a suitably chosen second step of quadrature demodulation or both; bandpass and bandstop filters can be obtained as combinations of lowpass and highpass filters.
TL;DR: In this paper, active filters were constructed using a combination of thin film and integrated circuits using a fifth-order Chebyshev function and the method of realization was to split the transfer function into quadratic and linear factors with each factor then realized separately.
Abstract: Microminiature active filters have been constructed using a combination of thin film and integrated circuits. The advantages of such an approach are discussed. The filter required could be met by a fifth-order Chebyshev function and the method of realization was to split the transfer function into quadratic and linear factors with each factor then realized separately. The tolerances required have been examined using a Monte Carlo computer program and the results are discussed. A filter constructed for use in p.c.m. systems is described.
TL;DR: Gain-frequency and transient responses of a number of typical filters are compared and it is shown that it is impossible to design a filter type that is at the same time ideal for observing short-lastingoustic phenomena like heart sounds as well as long-lasting acoustic phenomena like murmurs.
Abstract: Investigations and theoretical considerations show that it is impossible to design a filter type that is at the same time ideal for observing short-lasting acoustic phenomena like heart sounds as well as long-lasting acoustic phenomena like murmurs. It is shown that this impossibility is related to the selective properties and transient response of the filters. The use of high-pass filters having a low cut-off frequency, with gradual slopes of attenuation, and high cut-off frequency filters with a steep slope of attenuation, is advocated for phono-cardiography. Recently, cardiologists have expressed interest in the implications of using the various types of filters. In this paper, gain-frequency and transient responses of a number of typical filters are compared. The analytical procedure for obtaining the responses is briefly introduced.
TL;DR: In this article, the design procedures for interdigital and comb-line filters are summarized and the theory of these filters extended to include various aspects of design and performance which are not covered in the literature.
Abstract: The design procedures for interdigital and comb-line filters are summarized and the theory of these filters extended to include various aspects of design and performance which are not covered in the literature. The basic design equations are modified to give unified sets of expressions relating the resonator capacitances directly to the filter specification, and the theory of these filters is extended to include group delay, high-power breakdown effects and precise centre-frequency synthesis. In addition, the factors contributing to in-band dissipation loss are considered, and a method of predicting this loss in terms of the unloaded-Q of a slab-line resonator is given. Finally, a method of suppressing unwanted harmonic responses is outlined.
IBM1
TL;DR: This letter is intended to extend and clarify the methods of obtaining digital filters given in the above paper, especially those regarding quantization errors.
Abstract: This letter is intended to extend and clarify the methods of obtaining digital filters given in the above paper. Pertinent references to related literature are also included, especially those regarding quantization errors.
TL;DR: In this article, second-order RC filters are synthesized using two voltage amplifiers with gains A1 and A2 as the natural frequency depends on A1 only, and the damping factor depends on a 1 and 2 gain.
Abstract: Second-order RC filters are synthesized using two voltage amplifiers with gains A1 and A2 As the natural frequency depends on A1 only, and the damping factor depends on A1 and A2, these factors can be chosen consecutively by varying the two gains The passive components need not have variable or accurate values This feature is particularly useful in the realization of filters operating below 1 Hz, and cutoff frequencies down to at least 10-3 Hz can be obtained by exploiting the high input resistance of MOS transistors
TL;DR: In this article, the authors present the theory and design procedures for filters having two-pole maximally flat response functions, i.e., the resonating mode is the TE 02 circular electric mode, for three of the resonators.
Abstract: Interest in circular-electric mode channel-dropping filters has been stimulated by recent advances in the repeater art. This paper presents the theory and establishes design procedures for filters having two-pole maximally flat response functions. The basic structure uses mode-conversion resonators, i.e., the resonating mode is the TE 02 circular electric mode, for three of the resonators. The rejection filter portion of the structure is conventional in that two resonators separated by an odd multiple of π/2 radians realize the desired characteristic. The branching filter is novel in that a rectangular waveguide is wrapped around a mode-conversion resonator and coupled to the TE 02 resonating mode via a multiplicity of apertures. The rectangular guide is then resonated to permit realization of the two-pole branching filter. The theory developed is an extension of Marcatili's original work on mode-conversion resonators. The mode-conversion resonator parameters are related to the elements of a lumped constant prototype network thus extending the utility of mode-conversion resonators. Experimental results are presented on several filter models. The agreement between theory and experiment is generally good. Four filters were developed for use in an all solid-state repeater experiment with successful results.
IBM1
TL;DR: It has been demonstrated that spatial filters can be produced which contain not only amplitude information but also a record of the desired phase, which is done by applying holographic techniques in producing matched filters.
Abstract: The application of spatial filtering has recently received new impetus. It has been demonstrated that spatial filters can be produced which contain not only amplitude information but also a record of the desired phase. This is done by applying holographic techniques in producing matched filters, i.e., filters that represent the complex conjugate of the Fourier transform of the object function. Filters of a new kind, called binary spatial filters, have several advantages over holographically produced matched filters. First, since the transmittances of the new filters have values only of 0 or 1, oversized representations can be conveniently produced by a computer-guided plotter, and then photo-graphically reduced to the desired size. Second, the filter function need not exist physically; it must only be capable of mathematical description for the computer. Third, not only binary matched filters can be generated by computer, but also filters for a variety of other image-processing operations, such as code translation and differentiation.© (1967) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this article, a normalized low-pass prototype filter, terminated in equal value resistances, is considered and the insertion loss is given, as a function of normalized frequency and value of the terminating resistance.
Abstract: A normalized low-pass prototype filter, terminated in equal value resistances, is considered and the insertion loss is given, as a function of normalized frequency and value of the terminating resistance. The root-locus of the poles of the insertion-loss function is plotted showing the effect of variation of the value of the termination and comparison is made with the pole locations of Butterworth and Chebyshev filters of the third order. The treatment is extended to two identical prototype filters in cascade and in this case the root-locus of the poles of the insertion-loss function is compared with the poles of fifth order Butterworth and Chebyshev filter functions. Insertion-loss curves are given for various terminations for both single and cascaded filters.