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.

Embedded programmable filter for disk drive velocity control

Abstract: A disk drive having a motor and a velocity control loop, which includes a frequency detector and a filter. The filter includes a filter section and an accumulator. The filter is programmable in that filter coefficient(s) are dynamically received by the filter section. One embodiment of the filter section is an infinite impulse response filter. One embodiment of the filter is a digital integrated circuit. A method for compensating a control loop by infinite impulse response filtering and accumulating. The control loop may be a position, velocity, acceleration or force control loop. A programmable digital integrated circuit for compensating a velocity control loop having a filter section cascaded with an accumulator. The integrated circuit may include memory for storing filter coefficient(s) for the filter section, thereby not requiring external components.

Common-Mode DC-Bus Filter Design for Variable-Speed Drive System via Transfer Ratio Measurements

Abstract: Filters used in electromagnetic interference suppression are often described in literature on drive systems and have become a standard solution in industry. The effect of the commercial off-the-shelf filter depends significantly on how it is installed. A model that includes the installation parameters is made first and then the parameters of the model are extracted by transfer ratio measurements. One possibility is to include the filter on the dc-bus inside the converter. The differential mode DC-bus filter is well known, but the common-mode DC-bus filter has received little attention. Our model is used to show that the common-mode DC-bus filter can achieve the same or even better suppression of common-mode noise by careful design. The transfer ratio is used to evaluate the performance of filter design.

Single-Filter Structure With Tunable Operating Frequency in Noncontiguous Bands

Abstract: In this paper, we present a frequency-tunable substrate-integrated waveguide bandpass filter of which the operating frequency band can be switched between $S$ -band and $X$ -band. One of unique features of the presented filter is that a single-filter structure can replace a filter bank composed of an $S$ -band filter, an $X$ -band filter, and two switches at input and output ports for selecting one of two filters. In addition, the filter can tune the center frequency in each band. This paper provides the design method, fabrication, and measurement of the presented filter structure.

Miniaturized reconfigurable filter using PIN diode for UWB applications

Abstract: This paper reports a new compact design of UWB reconfigurable filter which switches from bandstop to bandpass filter using pin-diode. First, a unit cell is developed which consist of two bended open stubs of quarter-wavelength and a connecting stub of half-wavelength. Two unit cells are cascaded by inductive stub to form a bandstop filter. Avago’s RF pin diode is used to switch the filter from bandstop to bandpass filter at the same resonant frequency. The equivalent circuit model and its parameters are extracted. The measurement results for bandstop filter shows a rejection bandwidth is 5.2 GHz and the insertion loss in the passband is 0.6 dB. For the bandpass filter, the insertion loss is 2.1 dB and 3-dB bandwidth is from 3.6 GHz to 10.5 GHz. The area of novel unit cell filter is ( λ g /4)2 at the centre frequency of the bandstop, while the area of the filter realized using the non bending stubs and connecting lines is 2( λ g /4)2 for the same bandstop characteristics.

A 1 GHz OTA-based low-pass filter with a high-speed automatic tuning scheme

Abstract: A continuous-time 4th-order equiripple linear phase G m -C filter with an automatic tuning circuit is presented A high speed OTA based on the inverter structure is realized The combined CMFF and CMFB circuit ensures the input and output common-mode stability The gain performance could be maintained by combining a negative resistor at the output nodes Transconductance tuning can be achieved by adjusting the bulk voltage by using the Deep-NWELL technology Through the use of the OTA as a building block with a modified automatic tuning scheme, the filter -3 dB cutoff frequency is 1 GHz with the group delay less than 4% variation up to 15 fc frequency The -43 dB of IM3 at filter cutoff frequency is obtained with -4 dbm two tone signals Implemented in 018-mum CMOS process, the chip occupies 1mm2 and consumes 175 mW at a 15-V supply voltage