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Voltage-controlled filter

About: Voltage-controlled filter is a research topic. Over the lifetime, 5514 publications have been published within this topic receiving 70872 citations. The topic is also known as: VCF.


Papers
More filters
Patent
Shogo Inoue1, Jun Tsutsumi1, Motoaki Hara1, Masufumi Iwaki1, Takashi Matsuda1, Masanori Ueda1 
30 Sep 2009
TL;DR: In this paper, the resonance frequency of the resonators is set higher than the passband frequency of a filter, which improves the capacitor Q value, thus enabling the realization of a low-loss balance filter.
Abstract: In a high frequency device, resonators (IDT capacitors) that function as capacitors are included in a lumped constant balun included in a filter or duplexer, and furthermore, the resonance frequency of the IDT capacitors is set higher than the passband frequency of the filter. This improves the capacitor Q value, thus enabling the realization of a low-loss balance filter.

19 citations

Journal ArticleDOI
TL;DR: In this paper, a modular cascade H-bridge active power filter with a switching strategy is proposed to reduce voltage stress across the filter inductor and to reduce the average switching frequency.
Abstract: A novel design of a multi-level shunt active power filter using a modular cascade H-bridge is presented in this article. The proposed approach enables a modular approach in the design of a multi-level active power filter. As an illustration, a five-level H-bridge active power filter with a novel switching strategy has been implemented. The design is able to reduce the voltage stress across the filter inductor and to reduce the average switching frequency. Proportional plus integral controllers have been implemented for the current control loop, overall voltage control loop, and voltage balancing loop. A feedforward controller has also been added to the current control loop to improve the current tracking. By delaying the firing time of one of the H-bridges, five levels can be realized from a cascade H-bridge active power filter. The proposed switching strategy and the realization of the five-level switching scheme are presented. Experimental results are included to demonstrate the effectiveness o...

19 citations

Patent
Enn Vali1
08 Jun 1978
TL;DR: In this article, a flexible notch filter for use in a servo system to eliminate natural mechanical resonance was proposed, where the in-phase output of the filter is fed back into the filter.
Abstract: This invention relates to a flexible notch filter for use in a servo system to eliminate natural mechanical resonance. The filter is an improved "twin-T" type where the "in-phase" output of the filter is fed back into the filter. Varying the feedback varies the bandwidth of the filter. The improved filter further provides for attenuation control in addition to control of the center frequency of the filter. The advantage of this filter over prior art designs is that one filter may be manufactured and adapted to be used in many servo systems since the filter can be easily adjusted to effectively eliminate the natural resonating frequency of the machine in addition to reducing phase lag at frequencies below the center frequency of the notch filter.

19 citations

Journal ArticleDOI
01 Nov 1998
TL;DR: In this paper, the authors present a feasibility study of a shunt-series active power filter to be used with three-phase thyristor controlled rectifiers, which is based on two active power units: one shunt filter connected to the AC side and one series filter connected on the DC side of the rectifier.
Abstract: The authors present a feasibility study of a shunt–series active power filter to be used with three-phase thyristor controlled rectifiers. The proposed active filter is based on two active power units: one shunt filter connected to the AC side and one series filter connected to the DC side of the rectifier. The filters may have a common DC link and the shunt filter is controlled using the concepts of the instantaneous real and imaginary powers (p–q power theory). The series filter is controlled in such a way as to cancel the output voltage ripple of the rectifier. Digital simulation results obtained from an electromagnetic transient program (EMTP) are presented to validate this study. Experimental results obtained with a small-scale laboratory prototype consisting of shunt and series filter operating separately are also presented to show their benefits.

19 citations

Patent
10 Dec 1979
TL;DR: In this paper, an active microwave filter for both bandpass and notch filter applications is described, the filter incorporating a distributed resonator to which is coupled an amplifier which provides a positive feedback and cancels the net dissipation in the resonator.
Abstract: An active microwave filter for use in both bandpass and notch filter applications is herein described, the filter incorporating a distributed resonator to which is coupled an amplifier which provides a positive feedback and cancels the net dissipation in the resonator.

19 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20239
202229
20201
20188
2017150
2016199