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Butterworth filter

About: Butterworth filter is a research topic. Over the lifetime, 6187 publications have been published within this topic receiving 69070 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, a class of model-based filters for extracting trends and cycles in economic time series is presented, which are derived in a mutually consistent manner as the joint solution to a signal extraction problem in an unobserved-components model.
Abstract: A class of model-based filters for extracting trends and cycles in economic time series is presented These lowpass and bandpass filters are derived in a mutually consistent manner as the joint solution to a signal extraction problem in an unobserved-components model The resulting trends and cycles are computed in finite samples using the Kalman filter and associated smoother The filters form a class which is a generalization of the class of Butterworth filters, widely used in engineering They are very flexible and have the important property of allowing relatively smooth cycles to be extracted from economic time series Perfectly sharp, or ideal, bandpass filters emerge as a limiting case Applying the method to quarterly series on US investment and GDP shows a clearly defined cycle

277 citations

Journal ArticleDOI
TL;DR: In this article, a new resonator-embedded cross-coupled filter, constructed by stepped-impedance hairpin resonators and miniaturized hairpin resonance, is presented.
Abstract: Stepped-impedance resonators have been thoroughly studied in this paper. Two equations for odd- and even-mode resonance are derived from a new network model. The size and resonant frequencies of the resonator could then be designed based on these two equations. A new resonator-embedded cross-coupled filter, constructed by stepped-impedance hairpin resonators and miniaturized hairpin resonators is presented. This new filter is very compact and has lower spurious response. A 0/spl deg/ feed structure, which adds two transmission zeros to the filter response, is also studied. The two zeros are so close to the passband that the selectivity and out-of-band rejection of the filter are significantly increased. The design has been verified by experiment results.

272 citations

Proceedings Article
01 Jan 2004
TL;DR: In this article, the ring filter is used to control the attenuation pole frequency by adjusting both the ring and the stub impedance, and the circuit conditions of two attenuation poles at either side of the passband are given together with controlling them.
Abstract: To realize an Ultra Wideband (UWB) bandpass filter (BPF) in wireless communications[1], a device is developed using a new Ring Filter. The Ring Filter is compact, with low insertion loss, sharp rejection and a constant group delay within the UWB passband. The Ring Filter is made to control the attenuation pole frequency by adjusting both the ring and the stub impedance. A center frequency and a bandwidth of the 5-stage UWB BPF are designed based on the transmission line model. The circuit conditions of two attenuation poles at either side of the passband are given together with controlling them.

269 citations

Journal ArticleDOI
TL;DR: Explicit formulas for designing lattice wave digital filters of the most common filter types, for Butterworth, Chebyshev and Cauer parameter responses, were derived in this paper.
Abstract: Explicit formulas are derived for designing lattice wave digital filters of the most common filter types, for Butterworth, Chebyshev, inverse Chebyshev, and Cauer parameter (elliptic) filter responses. Using these formulas a direct top down design method is obtained and most of the practical design problems can be solved without special knowledge of filter synthesis methods. Since the formulas are simple enough also in the case of elliptic filters, the design process is sufficiently simple to serve as basis in the first part (filter design from specs to algorithm) of silicon compilers or applied to high level programmable digital signal processors.

259 citations

Journal ArticleDOI
TL;DR: In this paper, a simple technique for the exact synthesis of selective bandpass filters for wavelength division multiplexing (WDM) systems is presented, which consist of direct-coupled ring resonators or cascaded Bragg gratings.
Abstract: A simple technique for the exact synthesis of selective bandpass filters for wavelength division multiplexing (WDM) systems is presented. The filters consist of direct-coupled ring resonators or cascaded Bragg gratings. The proposed technique permits the calculation of the physical dimensions of the optical structures given the desired frequency response of the filter in terms of bandwidth, free spectral range, out-of-band rejection, and frequency characteristic. The technique, explained in detail for Butterworth and Chebyshev frequency responses, is exact, uses closed-form formulae, and is physically well based. The resulting devices are very compact, have a high out-of-band attenuation, and are suitable for high-density integrated optics. Several filters for applications such as channel add-drop, channel selection, demultiplexing, multichannel filtering, and interleavers are designed, analyzed, and discussed in the paper.

248 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202322
202282
202140
202059
201941
201864