scispace - formally typeset
Search or ask a question
Topic

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
Journal ArticleDOI
TL;DR: In this article, an ultra-selective filter for 3G and 4G wireless applications is presented, which consists of 22 resonators and five cross couplings that produce ten transmission zeros.
Abstract: An ultra-selective filter for third-generation (3G) and fourth-generation wireless application is presented. The demonstrated filter consists of 22 resonators and five cross couplings that produce ten transmission zeros. The filter was designed at 1950-MHz center frequency with a 20-MHz bandwidth to meet existing 3G wireless applications. The measured filter data shows excellent selectivity, better than 30-dB/100-kHz skirt slopes, and 90 dB of rejection at 350 kHz from the band edge. This filter performance surpasses the performance of a 50-pole Chebyshev filter. In order to fit a large number of resonators into a limited wafer area, a new compact resonator was developed. The filter was fabricated using a YBCO thin film on a 2-in MgO wafer.

93 citations

Journal ArticleDOI
TL;DR: An adaptive analog continuous-time biquadratic filter is realized in a 2- mu m digital CMOS process for operation at 300 kHz and nonidealities of an all-analog implementation are discussed, along with suggestions to improve performance.
Abstract: An adaptive analog continuous-time biquadratic filter is realized in a 2- mu m digital CMOS process for operation at 300 kHz. The biquad implements the notch, bandpass and low-pass transfer functions. The only parameter adapted is the resonant frequency of the biquad, which is identical to the notch frequency and the bandpass center frequency. The update method is based on a least-means-square algorithm which adapts the notch frequency to minimize the power at the notch filter output. The actual update is modified to reduce the circuit complexity to one biquad and one correlator. When the filter is tracking a sinusoid, this update generates a ripple-free gradient that decreases tracking error. Applications include phase-frequency detectors, FM demodulators (linear and frequency shift keying), clock extractors, and frequency acquisition aids for phase-locked loops and Costas loops. Measured results from experimental prototypes are presented. Nonidealities of an all-analog implementation are discussed, along with suggestions to improve performance. >

93 citations

Patent
Liza G. Boland1, Johan Janssen1
18 Dec 2000
TL;DR: In this paper, a filter structure is provided that facilitates the use of the filter as either a continuous delay Farrow filter or a selectable delay polyphase filter, and an inversion of Farrow filters is presented.
Abstract: A filter structure is provided that facilitates the use of the filter as either a continuous delay Farrow filter or a selectable delay polyphase filter. The less complex polyphase filter is used when the desired scale substantially corresponds to a defined phase of the polyphase filter, or when time or power is not available to achieve the desired scale exactly; otherwise, the continuous delay Farrow filter is used. By providing an ability to switch to a continuous delay, the number of stages of the polyphase filter can be reduced. Additionally, an inversion of a Farrow filter is presented that provides for a continuous delay decimation filter with substantially reduced computational complexity compared to a direct embodiment of a Farrow filter. This inverted filter is also configurable as a polyphase filter, to provide selectable scale-resolution capabilities.

93 citations

Proceedings ArticleDOI
05 Jun 2000
TL;DR: With this new filter and using multiple tacho references, waveforms, as well as amplitude and phase may be extracted without the beating interactions that are associated with conventional methods.
Abstract: The filter characteristics of the Vold-Kalman (1993, 1960, 1961) order tracking filter are presented. Both the frequency response as well as the time response and their time-frequency relationship have been investigated for different filter types and guidelines for optimum choice of filter parameters are presented. The Vold-Kalman filter allows for the high performance simultaneous tracking of orders in systems with multiple independent shafts. With this new filter and using multiple tacho references, waveforms, as well as amplitude and phase may be extracted without the beating interactions that are associated with conventional methods. Orders extracted as waveforms have no phase bias, and may hence be used for playback, synthesis and tailoring.

92 citations

Journal ArticleDOI
TL;DR: A new method to design prototype filters for conventional cosine-modulated pseudo-quadrature mirror filter (QMF) banks is presented, and the 3-dB cutoff frequency of the filter obtained at /spl pi//2M is set.
Abstract: We present a new method to design prototype filters for conventional cosine-modulated pseudo-quadrature mirror filter (QMF) banks. This method is based on windowing, and sets the 3-dB cutoff frequency of the filter obtained at /spl pi//2M. In this way, the filter bank performance can be significantly improved compared to other existing design methods.

92 citations


Network Information
Related Topics (5)
Capacitor
166.6K papers, 1.4M citations
86% related
Amplifier
163.9K papers, 1.3M citations
85% related
Voltage
296.3K papers, 1.7M citations
84% related
CMOS
81.3K papers, 1.1M citations
83% related
Integrated circuit
82.7K papers, 1M citations
82% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20239
202229
20201
20188
2017150
2016199