485 research outputs found

    Design of doubly-complementary IIR digital filters using a single complex allpass filter, with multirate applications

    Get PDF
    It is shown that a large class of real-coefficient doubly-complementary IIR transfer function pairs can be implemented by means of a single complex allpass filter. For a real input sequence, the real part of the output sequence corresponds to the output of one of the transfer functions G(z) (for example, lowpass), whereas the imaginary part of the output sequence corresponds to its "complementary" filter H(z)(for example, highpass). The resulting implementation is structurally lossless, and hence the implementations of G(z) and H(z) have very low passband sensitivity. Numerical design examples are included, and a typical numerical example shows that the new implementation with 4 bits per multiplier is considerably better than a direct form implementation with 9 bits per multiplier. Multirate filter bank applications (quadrature mirror filtering) are outlined

    Digital generator protection

    Get PDF
    Imperial Users onl

    Design and implementation of digital wave filter adaptors

    Get PDF

    Modern VLSI Analogue Filter Design: Methodology and Software Development

    Get PDF
    This thesis describes various approaches for the design of modern analogue filters and provides a practical filter and equaliser design aids system XFILT. The thesis begins by placing the analogue filter design technique and software into a historical and technology perspective. The evolution of the analogue filter is traced from early work, through the passive-RLC to transconductor-C and switched-current realisations. The software development in VLSI analogue filter automation is reviewed. For SC filter design, a cascade SC design approach which includes a novel pole-zero pairing method and a comprehensive comparison of SC filter realisation using different biquads are presented. Very useful guidelines for the choice of a suitable biquad structure according to the nature of the filter problem are presented. The canonical realisations of SC filter are studied. The multirate SC system design is described. Several strategies and the algorithms for multirate SC system design are proposed. In transconductor-C filter design research, the definition of a canonical ladder based transconductor-C filter is introduced, and two canonical ladder based transconductor-C filter design approaches are proposed. The ladder based transconductor-C equaliser design is also discussed. A practical video frequency transconductor-C filter and equaliser design is given to demonstrate the utility of the matrix design method and the design software. A new approach to realise exact ladder based SI filter with first and second generation memory cell has been proposed. The bilinear transformation is used in the design procedure. Eight different SI ladder based structures can be obtained for one prototype ladder. Therefore it provides SI filter designers with various circuit choices based on different requirement such as area, maximum ratio of transistor aspect ratio limit, sensitivity or noise performance. Techniques to improve dynamic range and reduce circuit parameter spread are also presented. The proposed approach is well suited for a computer compiler implementation. A suitability study of each decomposition method for different filtering applications is also carried out and a general guideline for the choice of different decomposition methods is obtained. A comparison study on SI filter sensitivity performance based on first generation and second generation memory cells is carried out. Using four filter examples, it is demonstrated that SI filters based on a second generation SI memory cell have good sensitivity performance. For SI filters based on first generation memory cells, it is shown that a high ratio of clock frequency to cutoff frequency in the lowpass case, or a high ratio of clock frequency to midband frequency in the bandpass case would introduce high sensitivity. A novel approach for SI ladder filter based on the S2I integrator is also proposed and a canonical realisation for SI filter based on S2I integrator is developed. Examination of SI equaliser design reveals that cascade structure is a better candidate than ladder based structure. Multirate SI filter system design is also studied. Finally, a very brief introduction to the assembly of the design methods in this thesis into a software package XHLT for VLSI analogue filter and equaliser design is given. The user aspects of XFILT have been discussed and various capabilities of XFILT are demonstrated. Several advanced facilities which remove traditional design limitations are illustrated. The philosophy of the system is explained. It is shown that the distinguished features of XFILT are Ease of Use. General Applicability, and Ease of Extension. The system structure is described and the graphics interface which acts both as user friendly interface and a system manager of all the software is outlined. Fabricated SC, transconductor-C, and SI filter and equaliser have been designed by using XFILT. The system is under further enhancement toward a commercial product

    Analogue filter networks: developments in theory, design and analyses

    Get PDF
    Not availabl

    An active filter design program (theory and application)

    Get PDF
    This thesis deals with the design of filters in the frequency domain. The intention of the thesis is to present an overview of the concepts of filter design along with two significant developments: a comprehensive filter design computer program and the theoretical development of an Nth order elliptic filter design procedure. The overview is presented in a fashion which accents the filter design process. The topics discussed include defining the attenuation requirements, normalization, determining the poles and zeros, denormalization and implementation. For each of these topics the text ad dresses the fundamental filter types (low pass through band stop). Within the topic of determining the poles and zeros, three classical approximations are discussed: the Butterworth, Chebyshev and elliptic function. The overview is concluded by illustrating selected methods of implementing the basic filter types using infinite gain multiple feedback (IGMF) active filters. The second major portion of the thesis discusses the structure, use and results of a computer program called FILTER. The program is very extensive and encompasses all the design processes developed within the thesis. The user of the program experiences an interactive session where the design of the filter is guided from parameter entries through the response evaluation and finally the determination of component values for each stage of the active filter. Complete examples are given. Included within the program is an algorithm for determining the transfer function of an Nth order elliptic function filter. The development of the theory and the resulting design procedure are presented in the appendices. The elliptic theory and procedure represent an important result of the thesis effort. The significance of this development stems from the fact that methods of elliptic filter design have previously been too disseminated in the literature or inconclusive for an Nth order design approach. Included in this development is a rapidly converging method of determining the precise value of the elliptic sine function. This function is an essential part of the elliptic design process

    Digital Filters

    Get PDF
    The new technology advances provide that a great number of system signals can be easily measured with a low cost. The main problem is that usually only a fraction of the signal is useful for different purposes, for example maintenance, DVD-recorders, computers, electric/electronic circuits, econometric, optimization, etc. Digital filters are the most versatile, practical and effective methods for extracting the information necessary from the signal. They can be dynamic, so they can be automatically or manually adjusted to the external and internal conditions. Presented in this book are the most advanced digital filters including different case studies and the most relevant literature

    Biomechatronics: Harmonizing Mechatronic Systems with Human Beings

    Get PDF
    This eBook provides a comprehensive treatise on modern biomechatronic systems centred around human applications. A particular emphasis is given to exoskeleton designs for assistance and training with advanced interfaces in human-machine interaction. Some of these designs are validated with experimental results which the reader will find very informative as building-blocks for designing such systems. This eBook will be ideally suited to those researching in biomechatronic area with bio-feedback applications or those who are involved in high-end research on manmachine interfaces. This may also serve as a textbook for biomechatronic design at post-graduate level
    corecore