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
TL;DR: In this paper, a versatile voltage-mode universal biquad filter using two single-output-operational transconductance amplifiers (OTAs), one differential difference current conveyor (DDCC) and two capacitors is proposed.
Abstract: A novel electronically tunable versatile voltage-mode universal biquad filter by using two single-output-operational transconductance amplifiers (OTAs), one differential difference current conveyor (DDCC) and two capacitors is proposed. The proposed circuit, which can be used as either a four-input single-output universal filter or a single-input three-output multifunction filter with the same topology. Besides, the new circuit offers the following advantageous features: realization of all the non-inverting and inverting biquadratic filter signals from the same configuration, no need to employ inverting-type input signals, no need to component-matching conditions and low passive sensitivity performance.
32 citations
Journal Article•
TL;DR: In this paper, the authors present a detailed review of the error models for INS/GPS integration and focus in detail on designing filtering methods for improving attitude accuracy in the bandwidth in which an inertial system does not benefit from frequent GPS position/velocity updates, including a spectral technique for dither spike removal and a class of low-pass finite-impulse response (FIR) filters operating in forward/backward manner.
Abstract: Stringent requirements on the accuracy of attitude determi- nation are currently a major challenge for strapdown INS/GPS integration, which is at the core of self-contained airborne remote sensing and mapping systems. This paper reviews the error models for INS/GPS integration and focuses i n detail on designingfiltering methodsfor improvingattitudeaccuracyin the bandwidth in which an inertial system does not benefit from frequent GPS position/velocity updates. Several fltering methods are designed based on the spec- tral analysis of the raw inertial signal in a dynamic environ- ment. These include a spectral technique for dither spike removal and a class of low-pass finite-impulse-response (FIR] filters operatinginforward/backward mannerfor achieving zero phase distortion. The orientation performance of the whole system with different filters i s evaluated b y comparing it to the "true" attitude information provided by a photo- grammetric block adjustment. Results show clearly that the choice of an appropriatefilter is decisivefor attitude accuracy. Overall, the INS/GPS integration combined with the most suitable pre-filtering method agrees with the external orien- tationreferenceto0.005"(19')RMS overthewholetestperiod, while the flight-line consistency is typically 0.003" (1U')RMS. The best filter in the comparison has an i?MS seven times smaller than the Butterworth filter which i s frequently applied i n the industrial designs of INS.
32 citations
TL;DR: In this article, a photonic signal processor topology is presented, which achieves high-Q value microwave bandpass filtering by means of a small free spectral range passive filter, while still operating the active stage with a large gain margin.
Abstract: A new photonic signal processor topology is presented, which achieves high-Q value microwave bandpass filtering. It significantly increases the Q by means of a small free spectral range passive filter, while still operating the active stage with a large gain margin. The filter response demonstrates very high resolution microwave signal filtering with a measured Q value of 983.
32 citations
TL;DR: In this article, a master/slave technique for digital tuning of a Gm-C filter's cut-off frequency is proposed, which relies on an accurate transconductance division technique, fixing the reference frequency independently from the filter cutoff frequency.
Abstract: A master/slave technique which allows digital tuning of a Gm-C filter's cut-off frequency is proposed. It relies on an accurate transconductance division technique, fixing the reference frequency independently from the filter cut-off frequency. The design of a digitally-tunable Gm-C switchable third/fifth- order Butterworth low-pass filter in a 0.13-mum 1.2-V CMOS process is also proposed. An extended tuning range (above 25:1) is obtained through the design of a linear very widely tunable transconductor. Measured results prove this chip to be compatible with the baseband part of direct-conversion cellular receivers, from GSM to W-CDMA, with a tuning accuracy better than 5% over the entire tuning range.
32 citations
Patent•
18 Nov 1998
TL;DR: In this paper, a notch filter (100) was proposed to augment the stopband rejection of a cascaded surface acoustic wave ladder filter (SAWL) with a pole at a desired passband.
Abstract: A notch filter ( 100 ) includes a parallel coupled delay line ( 104 ) and surface acoustic wave resonator ( 102 ) which provides a pole at a desired passband. The surface acoustic wave resonator ( 102 ) and the delay line ( 104 ) are configured to provide a zero at an undesired frequency or stopband. In this way, the notch filter ( 100 ) augments the stopband rejection of an associated cascaded surface acoustic wave ladder filter ( 105 ). The notch filter ( 100 ) also provides a pole at a desired frequency or passband such that losses due to the notch filter ( 100 ) at the desired passband are minimized, thereby improving overall insertion loss performance.
32 citations