Topic
Butterworth filter
About: Butterworth filter is a research topic. Over the lifetime, 6187 publications have been published within this topic receiving 69070 citations.
Papers published on a yearly basis
Papers
More filters
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TL;DR: Investigation of the theoretical design and physical implementation of a digital adaptive IIR filter to serve as an enhancement to the traditional active RC or passive RLC anti-aliasing filter indicates that the new filter performs well as compared to the Wiener filter in the stationary case.
Abstract: The goal of this research was to investigate the theoretical design and physical implementation of a digital adaptive IIR filter to serve as an enhancement to the traditional active RC or passive RLC anti-aliasing filter. This all-digital filter will reside directly on the DSP engine. As explained in the paper, the adaptive IIR filter is designed to process an oversampled signal coming from a single sensor to reject noise in an acquisition system. Differentiation between the noise and the signal is obtained by exploiting the different auto-correlation functions of the two signals. In contrast to oversampling techniques employed in sampled data systems that are designed to relax the requirements of an analog anti-aliasing filter, this filter will track a signal in the frequency domain. Several power spectral density plots are given to illustrate the performance of the new filter. The results also indicate that the new filter performs well as compared to the Wiener filter in the stationary case.
18 citations
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11 Aug 1996TL;DR: In this paper, an active input filter for a power factor correction (PFC) circuit employing ripple current cancellation is proposed to reduce the filter's size and cost, where ripple current can be filtered by an active circuit from the line current.
Abstract: An active input filter for a power factor correction (PFC) circuit employing ripple current cancellation is proposed to reduce the filter's size and cost. Switching ripple current can be filtered by an active circuit from the line current. Using a single stage passive filter with an active filter compensation circuit, a high filter can be synthesized to meet the electromagnetic interference (EMI) and power factor requirements. Analysis of the active filter and its design procedure are detailed. Simulation results are presented to verify the high order filter characteristics of the proposed scheme.
18 citations
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TL;DR: In this paper, a microstrip filter structure suitable for implementation of multi-order dual-band bandpass filter is presented, where two passbands have separate signal paths and the structures are assembled together novelly The independently controlled external and inter-resonator coupling can be simultaneously achieved.
Abstract: A microstrip filter structure suitable for implementation of multi-order dual-band bandpass filter is presented Two passbands have separate signal paths and the structures are assembled together novelly The independently controlled external and inter-resonator coupling can be simultaneously achieved The design is based on the conventional filter design method To take account of the effect between two passbands, the extraction of the external quality factor in one passband considers the effect of the other passbands and the direct source-load coupling introduced by the upper band structure is equivalent to an impedance inverter in the lower passband As an example, a fourth-order dual-band filter for WLAN applications is designed and fabricated The measured results have a good agreement with the simulated ones, which verifies effectiveness of the design
18 citations
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TL;DR: In this article, the independent component analysis (FastICA) is applied to separate the unknown noise signal from the unusual tension signal on the yarn twist machine, which can not only successfully separate the noise with different types but also remain the main tension signal information.
18 citations
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14 Jul 1997TL;DR: This paper presents a new discrete Lagrangian optimization method for designing multiplierless QMF (quadrature mirror filter) filter banks, and shows that this method can find designs that improve over Johnston's benchmark designs using a maximum of three to six ONE bits in each filter coefficient.
Abstract: In this paper, we present a new discrete Lagrangian optimization method for designing multiplierless QMF (quadrature mirror filter) filter banks. In multiplierless QMF filter banks, filter coefficients are powers-of-two (PO2) where numbers are represented as sums or differences of powers of two (also cabled Canonical Signed Digit-CSD-representation), and multiplications can be carried out as additions, subtractions and shifting. We formulate the design problem as a nonlinear discrete constrained optimization problem, using the reconstruction error as the objective, and other performance metrics as constraints. One of the major advantages of this formulation is that it allows us to search for designs that improve over the best existing designs with respect to all performance metrics, rather than finding designs that trade one performance metric for another. We show that our design method can find designs that improve over Johnston's benchmark designs using a maximum of three to six ONE bits in each filter coefficient.
18 citations