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
18 Dec 2008
TL;DR: In this paper, a novel design for improving the fractional order differential filter is put forward, where three kinds of novel first order differential filters are constructed by the interpolated method.
Abstract: In this paper, a novel design for improving the fractional order differential filter is put forward. By analyzing the frequency characteristic of typical fractional order differential filter, it can be seen that these kinds of differential filters have merits and demerits respectively and also could be complementary each other. So based on these features, three kinds of novel first order differential filters are constructed by the interpolated method. And then we choose a differential filter from these three kinds of filters which has much better frequency characteristic, also the improved IIR-type fractional order differential filter will be obtained by the method of continuous fraction expansion (CFE). The experiment result shows that the frequency response of the improved fractional order differential filter is more approximate to the ideal fractional order differential filter. And it also shows that the method put forward in the paper can improve the performance of the fractional order differential filter obviously under the premise of not increasing the structure complexity of the filter.
20 citations
TL;DR: In this article, a comprehensive design procedure for a CM EMC input filter is performed for a three-phase three-switch buck-type PWM rectifier, where a model of the CM noise propagation is developed and the relevant parasitic impedances are identified.
Abstract: The EMC input filter design for a three-phase pulse width modulated (PWM) rectifier is usually separated into the design of the differential mode (DM) and common mode (CM) stages. While for the DM filter design rules and procedures are well known and easier to predict, the CM filter design is often based on trial-and-error methods and/or on the experience of the designer. In the present study, a comprehensive design procedure for a CM EMC input filter is performed for a three-phase three-switch buck-type PWM rectifier. A model of the CM noise propagation is developed and the relevant parasitic impedances are identified. A capacitive connection from the star-point of the DM input filter to the capacitive centre point of the rectifier output voltage is proposed and the effect of this measure-concerning CM is verified. Finally, a two-stage CM filter is designed and compliance to the conducted emission (CE) requirements of CISPR 22 Class B is verified through measurements on a 5 kW prototype.
20 citations
24 Jun 2004
TL;DR: This paper uses the equiripple FIR low- pass filter by superimposing of the optimal method, the Butterworth IIR low-pass filter, the 8-point moving-average filter and the FIR filter designed by using a Kaiser window to compare the reduction of the embedded high-frequency noise.
Abstract: After an analog ECG signal is transferred into digital format, a suitable digital filter can be used to suppress the high-frequency embedded noise. In this paper, we use the equiripple FIR low-pass filter by superimposing of the optimal method, the Butterworth IIR low-pass filter, the 8-point moving-average filter and the FIR filter designed by using a Kaiser window. Furthermore, we combine the 8-point moving-average filter with the FIR filter designed by using a Kaiser window. In addition, we use the mean square error (M. S. E.) to estimate the effect of the digital filters in order to compare the reduction of the embedded high-frequency noise. Hence, we compute the mean square error with respect to the order, N, of these filters and plot the relationship between M. S. E. and N. Finally, we find the relationship between the CPU time and N.
20 citations
04 Dec 2005
TL;DR: In this paper, the authors proposed a new compact microstrip low-pass filter with broad stopband and sharp skirt characteristics, which is composed of a pair of parallel coupled-line and an open-stub.
Abstract: In this paper, we proposed a new compact microstrip low-pass filter with broad stopband and sharp skirt characteristics The philosophy of the structure behind this novel microstrip low-pass filter is simple as it is composed of a pair of parallel coupled-line and an open-stub With this configuration, a finite attenuation pole near the stopband cutoff frequency is available, and the notch frequency can be well controlled by adjusting the circuit parameters The design formulas are derived by using an equivalent-circuit model of a parallel coupled transmission line In order to validate the feasibility of the proposed design method, a 3-order Chebyshev low-pass filter with 001-dB ripple is designed, fabricated, and measured Experimental results agree well with the simulation and analytical results
20 citations
TL;DR: A sixth-order low-pass transconductor-C filter with a very wide tuning range (fc = 100 Hz to 10 MHz) is presented and a modified biquadratic topology is introduced to improve linearity performance of the filter over its tuning range.
Abstract: A sixth-order low-pass transconductor-C filter with a very wide tuning range (fc = 100 Hz to 10 MHz) is presented. The wide tuning range has been achieved without using switchable components or programmable building blocks. A single-stage folded cascode transconductor is employed to implement the proposed filter. A modified biquadratic topology is introduced to improve linearity performance of the filter over its tuning range. Power consumption of the filter scales linearly with cutoff frequency (60 pW/Hz/pole). Implemented in 0.18-μm complementary metal-oxide-semiconductor technology, the filter exhibits relatively constant noise and linearity performance over its entire tuning range and occupies a silicon area of 0.16 mm2 (0.027 mm2/pole).
20 citations