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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
Patent
08 Oct 1991
TL;DR: In this article, a low precision Finite Impulse Response filter (FIR) is provided for filtering in a digital interpolation operation, which includes two steps, a sampling rate conversion operation for interspersing zeroes between samples in an input sequence and a filtering step of filtering out images that result from this operation.
Abstract: A low precision Finite Impulse Response filter (FIR) is provided for filtering in a digital interpolation operation. The interpolation operation includes two steps, a sampling rate conversion operation for interspersing zeroes between samples in an input sequence and a filtering step of filtering out images that result from this operation. The filtering operation utilizes a FIR filter that utilizes low precision filter coefficients that are selected to tune the frequency response such that the low end frequency response including the pass band, the transition band, and the portion of the stop band immediately after the transition band provides a response equivalent to that commensurate with substantially higher precision FIR filter coefficients, with the high frequency end of the stop band gradually increasing. A second, low pass filter section is provided for filtering out the image energy that exists at the output of the FIR filter in the high frequency end of the stop band to provide an overall filter response that is commensurate to that utilizing substantially higher precision FIR coefficients in the filter section. The FIR filter coefficients utilized are restricted to the set of [-1, 0, +1] such that a multiplierless FIR filter can be realized. The FIR filter coefficients are obtained by processing the infinite FIR filter coefficients through a software delta-sigma quantizer which quantizes the output to the desired low precision FIR filter coefficients.

59 citations

Journal ArticleDOI
TL;DR: In this article, a fluidic-based approach for designing tunable coupled resonator bandpass filters is presented, which employs broadside coupled split ring resonators (SRR) with one of their open loop resonators constructed from liquid metal.
Abstract: A fluidic-based approach for designing tunable coupled resonator bandpass filters is presented. These filters employ broadside coupled split ring resonators (BC-SRR) with one of their open loop resonators constructed from liquid metal. The tuning mechanism is based on dynamically moving the liquid metal to reshape the resonator. To demonstrate the concept, a second order Butterworth filter with continuous tuning range from 650 to 870 MHz is designed and experimentally verified by utilizing PTFE tubing filled with liquid metal and Teflon solution. Due to an inductive external coupling mechanism and 180° rotated resonators, the filter exhibits a near constant 5% fractional bandwidth throughout its tuning range with > 10 dB return and <; 3 dB insertion loss. The filter is realized over a 1.27 mm thick Rogers 6010.2LM substrate and has an approximate footprint of 20 × 40 mm2.

58 citations

Journal ArticleDOI
TL;DR: A novel wide-tuning high-Q active bandpass filter utilizing the active inductors is presented, and issues of theactive inductor related to Q -enhancement, noise, linearity, and stability are considered.
Abstract: In this paper, design techniques for an integrated RF bandpass filter are discussed. A novel wide-tuning high-Q active bandpass filter utilizing the active inductors is presented. Issues of the active inductor related to Q -enhancement, noise, linearity, and stability are considered. The circuit has been fabricated in an 0.18-mum CMOS process, and the filter occupies the active area of 150 times 200 mum2. Measurement results show that the filter centered at 3.82 GHz with about 36-MHz bandwidth (3-dB) is tunable in frequency from about 1.92 to 3.82 GHz, and it exhibits -15- to 1-dB compression point at 2.44 GHz with approximately 60-MHz bandwidth while the dc power consumes 10.8 mW.

58 citations

Proceedings Article
01 Jan 2005
TL;DR: A new figure of merit is introduced for comparison of published low-pass tunable filters including noise, linearity, and tuning range, as well as intended as a channel-selection/anti-aliasing filter in the analog baseband part of a zero-IF radio receiver architecture for multimode mobile communications.
Abstract: A third-order G m -C Butterworth low-pass filter implementing G m -tuning and G m -switching to maximize the tuning range is described. This filter is intended to be used as a channel-selection/anti-aliasing filter in the analog baseband part of a zero-IF radio receiver architecture for multimode mobile communications. Its G m -switching feature allows extending the tuning range and adapting the power consumption. The filter's cutoff frequency ranges from 50 kHz to 2.2 MHz. An Input IP3 of up to +18 dBVp is achieved, for a total worst-case power consumption of 7.3 mW for both I and Q paths, and an effective area of less than 0.5 mm 2 in a 0.25-μm SiGe BiCMOS process. A new figure of merit is introduced for comparison of published low-pass tunable filters including noise, linearity, and tuning range.

58 citations

Journal ArticleDOI
TL;DR: In this paper, a back-to-back microstrip-CPW transition structure is proposed for ultra-wideband bandpass filter with an out-of-band rejection level of below -20.0 dB.
Abstract: A novel ultra-wideband bandpass filter based on a back-to-back microstrip-CPW transition structure is presented. The filter is composed of two microstrip-CPW transitions and a section of microstrip line used as a multiple-mode resonator. The filter has been investigated numerically and experimentally. Both simulated and measured results show that the filter has a good performance, including a small insertion loss, a group delay variation of less than 0.2 ns, stopband of up to 16.0 GHz at high frequencies, and an out-of-band rejection level of below -20.0 dB.

57 citations


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