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Showing papers on "Voltage-controlled filter published in 2012"


Proceedings ArticleDOI
05 May 2012
TL;DR: The 1 € filter ("one Euro filter") is a simple algorithm to filter noisy signals for high precision and responsiveness using a first order low-pass filter with an adaptive cutoff frequency.
Abstract: The 1 € filter ("one Euro filter") is a simple algorithm to filter noisy signals for high precision and responsiveness. It uses a first order low-pass filter with an adaptive cutoff frequency: at low speeds, a low cutoff stabilizes the signal by reducing jitter, but as speed increases, the cutoff is increased to reduce lag. The algorithm is easy to implement, uses very few resources, and with two easily understood parameters, it is easy to tune. In a comparison with other filters, the 1 € filter has less lag using a reference amount of jitter reduction.

264 citations


Journal ArticleDOI
TL;DR: In this paper, a hybrid active filter is proposed for mitigating the line-side harmonic currents of a three-phase 12-pulse diode rectifier used as the front end of a medium-voltage high-power motor drive.
Abstract: This paper describes a hybrid active filter intended for mitigating the line-side harmonic currents of a three-phase 12-pulse diode rectifier used as the front end of a medium-voltage high-power motor drive. This hybrid filter is characterized by series connection of a simple LC filter and a small-rated active filter. This circuit configuration brings low cost, small size, and light weight to the hybrid filter. A three-phase experimental system rated at 400 V and 15 kW is designed, constructed, and tested, which is a downscaled model of the medium-voltage motor drive system. In this experiment, the LC filter is tuned to the 11th-harmonic frequency, and the active filter is based on a three-level neutral-point-clamped pulsewidth modulation converter (NPC PWM) with a dc capacitor voltage as low as 28 V. This hybrid filter is connected on either first or fourth winding of a line-frequency transformer with a first Δ-winding voltage of 400 V in the primary, and a second Δ-winding voltage of 220 V, a third Y-winding voltage of 220 V, and a fourth Δ-winding voltage of 400 V in the secondary. Experimental results show that the hybrid filter performs satisfactory filtering in a range from no-load to full-load conditions.

209 citations


Journal ArticleDOI
TL;DR: In this article, a new type of bandstop-to-all-pass reconfigurable filter is developed and the relationship between resonator quality factor, filter bandwidth, and the all-pass response state is shown for the first time.
Abstract: The theory of a new type of bandstop-to-all-pass reconfigurable filter is developed in this work. A bandstop filter structure with both source-to-load and inter-resonator coupling is implemented. The synthesis equations are manipulated such that the signals in the filter's resonators and source-to-load transmission line can be made to constructively or destructively interfere at the output port through tuning of the resonant frequency of the filter's resonators. The relationship between resonator quality factor, filter bandwidth, and the all-pass response state is shown for the first time. The theory is proven through fabrication of a bandstop-to-all-pass filter with resonator unloaded quality factors greater than 500. Measured results show that the filter can continuously tune from insertion loss of 2.1 dB in the all-pass state to insertion loss of 69 dB in the bandstop state at the center frequency of the filter. Analog tuning of the attenuation level is also shown. The capability to switch from an all-pass to a variable-attenuation bandstop response enables a spectrally aware system to operate over wide bandwidths when interference levels are low and to dynamically add bandstop responses when interference affects its performance or signal equalization is required.

84 citations


Patent
04 May 2012
TL;DR: In this article, a single-photon receiver and a method for detecting a singlephoton are presented, which comprises a SPAD that receives a gating signal having a fundamental frequency in the 100 MHz to multiple GHz range, and a two-stage frequency filter for filtering the output of the SPAD, wherein the filter has: (1) a notch filter response at the fundamental frequency; and (2) a low-pass filter response whose cutoff frequency is less than the first harmonic of the fundamental value.
Abstract: A single-photon receiver and method for detecting a single-photon are presented. The receiver comprises a SPAD that receives a gating signal having a fundamental frequency in the 100 MHz to multiple GHz range. The receiver further comprises a two-stage frequency filter for filtering the output of the SPAD, wherein the filter has: (1) a notch filter response at the fundamental frequency; and (2) a low-pass filter response whose cutoff frequency is less than the first harmonic of the fundamental frequency. As a result, the frequency filter removes substantially all the frequency components in the SPAD output without significant degradation of the signal quality but with reduced complexity, cost, and footprint requirement relative to receivers in the prior art.

67 citations


Journal ArticleDOI
TL;DR: In this article, the properties of tunable wavelength pi'n/pin filters based on a-SiC:H multilayered stacked cells are studied both experimentally and theoretically.
Abstract: Characteristics of tunable wavelength pi'n/pin filters based on a-SiC:H multilayered stacked cells are studied both experimentally and theoretically. Results show that the device combines the demultiplexing operation with the simultaneous photodetection and self amplification of the signal. An algorithm to decode the multiplex signal is established. A capacitive active band-pass filter model is presented and supported by an electrical simulation of the state variable filter circuit. Experimental and simulated results show that the device acts as a state variable filter. It combines the properties of active high-pass and low-pass filter sections into a capacitive active band-pass filter using a changing capacitance to control the power delivered to the load.

61 citations


Journal ArticleDOI
TL;DR: In this paper, the authors presented a new methodology for the synthesis of tunable patch filters, which helps the designer to perform a theoretical analysis of the filter through a coupling matrix that includes the effect of tuning elements used to tune the filter.
Abstract: A new methodology for the synthesis of tunable patch filters is presented. The methodology helps the designer to perform a theoretical analysis of the filter through a coupling matrix that includes the effect of the tuning elements used to tune the filter. This general methodology accounts for any tuning parameter desired and was applied to the design of a tunable dual-mode patch filter with independent control of center frequency and bandwidth (BW). The bandpass filter uses a single triangular resonator with two etched slots that split the fundamental degenerate modes and form the filter passband. Varactor diodes assembled across the slots are used to vary the frequency of each degenerate fundamental mode independently, which is feasible due to the nature of the coupling scheme of the filter. The varactor diode model used in simulations, their assembling, the dc bias configuration, and measured results are presented. The theory results are compared to the simulations and to measurements showing a very good agreement and validating the proposed methodology. The fabricated filter presents an elliptic response with 20% of center frequency tuning range around 3.2 GHz and a fractional BW variation from 4% to 12% with low insertion loss and high power handling with a 1-dB compression point higher than .

59 citations


Patent
09 Sep 2012
TL;DR: In this article, a system for managing the changing state of an adaptive filter in an active noise control (ANC) system is described, where adaptive filter state storage stores copies of prior states of the adaptive filter.
Abstract: A system for managing the changing state of an adaptive filter in an active noise control (ANC) system is described. An adaptive filter state storage stores copies of prior states of the adaptive filter. A disturbance detector can detect either normal ambient noise or abnormal ambient noise. An adaptive filter state manager signals that a copy of a current state of the adaptive filter is to be repeatedly written to the state storage, so long as normal ambient noise is being detected. But when abnormal noise is detected, the state manager signals that the adaptive filter be restored to one of its prior states, from the copies stored in the state storage. Other embodiments are also described and claimed.

59 citations


Patent
Nadim Khlat1
30 Nov 2012
TL;DR: In this paper, the RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from a low-drop out (LDO) regulation circuit.
Abstract: This disclosure relates to radio frequency (RF) power converters and methods of operating the same. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out (LDO) regulation circuit, and an RF filter. The RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from the LDO regulation circuit. The RF filter is operable to alternate between a first RF filter topology and a second RF filter topology. In the first RF filter topology, the RF filter is configured to convert the pulsed output voltage from a switching circuit into the supply voltage. The RF filter in the second RF filter topology is configured to filter the supply voltage from the LDO regulation circuit to reduce a ripple variation in a supply voltage level of the supply voltage. As such, the RF filter provides greater versatility.

54 citations


Journal ArticleDOI
TL;DR: In this paper, a microstrip lowpass filter with compact size and an ultra-wide stopband is proposed, which can suppress the sixteenth harmonic response referred to a suppression degree of 15'dB.
Abstract: A new microstrip lowpass filter with compact size and an ultra-wide stopband is proposed. To achieve compact size and ultra-wide band rejection, both triangular patch resonators and radial patch resonators are introduced in the filter. To reduce the circuit size of the filter further, meander transmission lines are also adopted in the design. A demonstration filter with 3 dB cutoff frequency at 1 GHz has been designed, fabricated and measured. Results indicate that the proposed filter can suppress the sixteenth harmonic response referred to a suppression degree of 15 dB. Furthermore, the proposed filter exhibits a small size of 0.111 λg×0.091 λg, where λg is the guided wavelength at 1 GHz.

52 citations


Proceedings ArticleDOI
03 Apr 2012
TL;DR: In this paper, a single-ended (SE) and a differential 8-path N-path filter with passive frequency mixing are presented, which are power-matched in the input and output in the passband and provide a low insertion loss, high compression point and also low noise property.
Abstract: The huge growth of the number of wireless devices makes wireless coexistence an increasingly relevant issue. If radios operate in close proximity, blockers as strong as 0dBm may occur, driving almost any receiver in compression (note that 0dBm in 50Ω corresponds to a peak-to-peak voltage of half a 1.2V supply). Thus RF blocker filtering is highly wanted. However, fixed filters are undesired when aiming for multiband, software-defined or cognitive radio transceivers. Passive LC filters show limited Q and tunability. Recently frequency translated filtering has been proposed as a potential solution direction for high-Q filtering [1–5]. In [1,2] we showed that by applying the “N-path concept” [6], more than a decade of center frequency range with good linearity, compression point (P 1dB >0dBm, IIP3 >14dBm) and low noise is feasible for a bandpass (BP) filter. In [3] a notch filter with a combination of active and passive mixers is applied in a feedforward path realizing a BP filter. Moreover in [5] the low input impedance of a transimpedance amplifier with feedback is upconverted to create a notch filter at low frequencies (80MHz) suppressing TX leakage in an FDD system. In this work we explore the possibility to realize a notch filter applying the N-path concept at RF frequencies and in a completely passive way. A single-ended (SE) and a differential 8-path notch filter with passive frequency mixing are presented. The filters are power-matched in the input and output in the passband and provide a low insertion loss, high compression point and also low noise property, thus they can be utilized in front of a receiver to provide rejection of high-power blockers with a large frequency tuning range.

51 citations


Patent
10 Dec 2012
TL;DR: In this paper, a pre-shaping adaptive filter has been proposed to increase noise cancellation performance in a high frequency band during the presence of focused or narrow-band noise energy in a low frequency band.
Abstract: An active noise control (ANC) processor has an adaptive filter that uses a reference signal to produce an anti-noise signal, and an error signal to evaluate cancellation performance. An adaptive filter algorithm engine configures the filter coefficients of the adaptive filter, in accordance with pre-shaped versions of the error and reference signals. The pre-shaping filter has a high-pass transfer function and enables the adaptive algorithm engine to increase noise cancellation performance in a high frequency band during the presence of focused or narrow-band noise energy in a low frequency band. Other embodiments are also described and claimed.

Journal ArticleDOI
TL;DR: In this article, a compact lowpass filter with sharp cutoff frequency response and wide rejection bandwidth is proposed, which has a simple structure and comprises one microstrip coupled-line hairpin unit, one spiral slot and two open stubs.
Abstract: A compact lowpass filter (LPF) with sharp cutoff frequency response and wide rejection bandwidth is proposed. The proposed LPF has a simple structure and comprises one microstrip coupled-line hairpin unit, one spiral slot and two open stubs. A demonstration filter with 3 dB cutoff frequency at 2.0 GHz has been designed and fabricated. Theoretical and simulated results are presented, which are in good agreement with the measured results.

Journal ArticleDOI
TL;DR: In this article, the authors proposed a new tunable versatile current-mode universal filter with four inputs and three outputs, which employs three plus-type differential voltage current conveyors, two grounded capacitors and three grounded resistors.
Abstract: This paper presents a new tunable versatile current-mode universal filter with four inputs and three outputs. The proposed configuration employs three plus-type differential voltage current conveyors, two grounded capacitors and three grounded resistors. Its high impedance outputs enable easy cascading in current-mode operation. The circuit can be used as either a single-input and three-output or four-input and two-output. In the operation of single-input and three-output circuit, the bandpass, highpass and bandreject filtering responses can be realized simultaneously. In the operation of four-input and two-output circuit, both inverting and non-inverting type lowpass, bandpass, highpass, bandreject and allpass filtering responses can be simultaneously realized by selecting different four input current signals. The filter permits orthogonal controllability of the quality factor and resonance angular frequency by adjusting the grounded passive components. No component matching condition is required for realizing all the filter responses, and all the passive and active sensitivities are low. HSPICE simulation results based on using TSMC 0.18 μm 1P6M CMOS process technology and supply voltages ±0.9 V to verify the theoretical analysis.

Journal ArticleDOI
TL;DR: This brief presents a new bandpass filter for audio-frequency filter banks and provides a procedure for designing this filter, used in a 16-channel filter bank which has been fabricated in a 0.35- CMOS process.
Abstract: Analog filter banks befit remote audio- and vibration-sensing applications, which require frequency analysis to be performed with low-power consumption and with moderate-to-high precision. The precision of a filter bank depends on both the signal-path precision (i.e., dynamic range) and also the parameter precision (e.g., accuracy of the center frequencies). This brief presents a new bandpass filter for audio-frequency filter banks and provides a procedure for designing this filter. The filter is used in a 16-channel filter bank which has been fabricated in a 0.35- CMOS process. This filter bank has a dynamic range exceeding 62 dB and consumes only 63.6 when biased for speech frequencies. The filter bank's parameters are set via floating-gate current sources. This brief shows how to use these floating gates to obtain a versatile filter bank that can be precisely reprogrammed to arbitrary filter spacings and frequency weightings, with a parameter accuracy exceeding 99%.

Patent
02 Jul 2012
TL;DR: In this article, a first filter coupled to an antenna coupling network and a second filter, a power amplifier coupled to the first filter, an antenna connected to an AU coupling network, a pilot tone generator coupled to first filter and a first signal source connected to the power amplifier and first filter are described.
Abstract: Systems and methods are disclosed for an electronically adjustable signal filter system, which comprises, in some embodiments, a first filter coupled to an antenna coupling network and a second filter, a power amplifier coupled to the first filter, an antenna connected to an antenna coupling network, a pilot tone generator coupled to the first filter, and a first signal source connected to the power amplifier and first filter. In some embodiments, the power amplifier amplifies the first signal, the first filter places a notch into the first signal transmitted to the antenna coupling network, the antenna coupling network combines the first signal and a second signal received from the antenna and transmits a third signal to the second filter.

Journal ArticleDOI
TL;DR: A new filter structure is introduced here to suppress the sidelobes of radar signals that result from standard matched filtering to ensure adequate mainlobe-to-peak-sidelobe ratio (MSR) can be achieved.
Abstract: Pulse compression is an active research topic in radar systems. A problem in pulse compression is masking of small targets by the range sidelobes of large nearby targets. A new filter structure is introduced here to suppress the sidelobes of radar signals that result from standard matched filtering. The proposed filter is applicable for any type of binary coding signals. Several techniques are used to calculate the filter coefficients such as Wiener filter technique, Lagrange multiplier method, and linear programming (LP) algorithm. Also, a weighting function is utilized to shape the sidelobe energy in an iterative manner that will yield more sidelobe reduction. Comparison of the proposed filters and the matched filter shows that at the expense of insignificant loss in signal-to-noise ratio (LSNR), adequate mainlobe-to-peak-sidelobe ratio (MSR) can be achieved.

Journal ArticleDOI
TL;DR: A flexible current-reuse operational amplifier with a power-scaling technique is proposed to lower the power consumption, and the image-rejection ratio is improved by almost 20 dB by introducing an I/Q imbalance calibration circuit before the filter.
Abstract: A power-scalable reconfigurable filter with in-phase/quadrature (I/Q) imbalance calibration for a multimode Global Navigation Satellite Systems (GNSS) receiver is presented. The filter is reconfigurable as either a fifth-order complex bandpass filter exhibiting a tunable intermediate frequency (4.092, 6.138, 10.23, 12.296, 13.29, 18.4, and 20.442 MHz) and bandwidth (2.2, 4.2, 8, 10, and 18 MHz) or a third-order low-pass filter with tunable bandwidth (5 and 9 MHz). A flexible current-reuse operational amplifier with a power-scaling technique is proposed to lower the power consumption, and the image-rejection ratio is improved by almost 20 dB by introducing an I/Q imbalance calibration circuit before the filter. The filter, which was implemented in 65-nm CMOS, consumes 2.9-19.5 mW in different modes, with the I/Q calibration circuit consuming 0.9 mW.

Journal ArticleDOI
TL;DR: In this paper, a compact balanced bandpass filter is proposed using a novel circuit topology, which includes a differential resonator and a common resonator in the conventional quasi-lumped coupled-line circuit, instead of adopting quarterwavelength or halfwavelength transmission lines in the filter design.
Abstract: A compact balanced bandpass filter is proposed using a novel circuit topology, which includes a differential resonator and a common resonator in the conventional quasi-lumped coupled-line circuit, instead of adopting quarter-wavelength or half-wavelength transmission lines in the filter design. Based on this circuit topology, the balanced bandpass filter can support bandpass filtering function under differential-mode operation and exhibit bandstop filtering function under common-mode noise. By employing the advantage of the low-temperature co-fired ceramic fabrication technology, a compact balanced bandpass filter is centered at 3.42 GHz with fractional bandwidth 10.4% for differential signals and rejection band is from 1.48 to 7.4 GHz for the common-mode noise. Moreover, the proposed filter is able to introduce a transmission zero with excellent common-mode suppression (>;40 dB) within the differential-mode passband. The electrical size of this filter is 5.6 × 5.4 mm with the corresponding electrical size 0.113 × 0.109 λg, where λg is the guided wavelength at the center frequency 3.42 GHz. This compact balanced bandpass filter is suitable to be applied to the system-in-package technology for wireless application.

Journal ArticleDOI
TL;DR: In this article, a three-pole tunable notch filter with frequency and bandwidth control is proposed, which introduces no noticeable distortion of wideband code-division multiple access (WCDMA) waveforms with a power of 25 dBm at frequencies corresponding to the 30-40 dB nulls and at the - 3dB and - 6dB passband frequencies.
Abstract: This paper presents a high-performance three-pole tunable notch filter with frequency and bandwidth control. The filter is implemented using suspended-stripline resonators and planar 3-bit RF MEMS capacitive networks. A tuning range of 1.1-2.7 GHz with a 40-dB rejection bandwidth of 115±25 MHz is demonstrated with a passband insertion loss <; 0.8 dB. A 40-dB rejection bandwidth of 26-126 and 24-200 MHz is demonstrated at 1.6 and 2.0 GHz, respectively. The filter introduces no noticeable distortion of wideband code-division multiple-access (WCDMA) waveforms with a power of 25 dBm at frequencies corresponding to the 30-40 dB nulls and at the - 3-dB and - 6-dB passband frequencies. At the - 0.5-dB passband frequency, the filter can handle up to 30 dBm of WCDMA power with no measurable distortion. To our knowledge, this filter represents state-of-the-art tuning performance and power handling for planar notch filter designs. The application areas are in wideband cognitive radios with high interference levels.

Proceedings ArticleDOI
19 Apr 2012
TL;DR: In this article, the authors propose a systematic approach to design the output filter of a 10 kW, low-voltage 400 V ll, rms, four output phase, hard-switched AC source based on the Three-Level Neutral Point Clamped Voltage Source Converter topology.
Abstract: This paper proposes a systematic approach to design the output filter of a 10 kW, low-voltage 400 V ll,rms , fouroutput phase, hard-switched AC source based on the Three-Level Neutral Point Clamped Voltage Source Converter topology. Given specifications of the AC source, such as the voltage quality, the control performance or the conducted EMI at the output of the source, are translated into corresponding families of curves in the parameter space of the output filter. The area/volume enclosed by these curves represents the design space of the output filter in which all tuples (L f , C f ), e.g. for a single-stage LC-filter, fulfill every single AC source specification. From all possible filter parameters in the design space, the set of parameters resulting in the smallest filter volume, the lowest filter weight, the highest filter efficiency and/or the lowest filter costs can be selected.

20 Mar 2012
TL;DR: The effect on the letter accuracy (single-trial detection) provided by a linear support vector machine of a high-pass filter with cutoff frequencies from 0.1 to 1 Hz and a low-pass filters with cutofffrequency from 8 to 60 Hz is compared.
Abstract: According to recent literature, the most appropriate preprocessing to improve P300 detection is still unknown or at least there is no consensus about it. Research papers refer to different low-pass filters, high-pass filters, baseline, subsampling or feature selection. In this paper, using a database with 23 healthy subjects we compare the effect on the letter accuracy (single-trial detection) provided by a linear support vector machine of a high-pass filter with cutoff frequencies from 0.1 to 1 Hz and a low-pass filter with cutoff frequencies from 8 to 60 Hz. According to this study, the best combination is for a band-pass filter of 0.1 to 15 Hz.

Journal ArticleDOI
TL;DR: In this paper, an UHF third order bandpass filter based on an high-Q active inductor (AI) is described and measurement results, performed on a prototype board, are presented and compared with software simulations.
Abstract: In this article, an UHF third order bandpass filter based on an high-Q active inductor (AI) is described and measurement results, performed on a prototype board, are presented and compared with software simulations. The designed AI includes a passive variable phase- and amplitude-compensating network and a highly linear inverting amplifier, forming a gyrator-C architecture that gives to the filter also frequency and amplitude tuneability proprieties. The fabricated Butterworth filter has a center frequency of 600 MHz and a measured noise figure of 11 dB with a 5 dBm 1-dB compression point and a 82 dB dynamic range. All passive components values have been chosen to allow the circuit to be completely integrated in a standard IC design. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1426–1429, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26857

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a tunable, narrow-band, micromechanical filter whose bandwidth and center frequency can be adjusted independently. But the performance of the proposed filter is limited by the fact that it requires two micro-resonators coupled using a middle electrode.
Abstract: This paper introduces a tunable, narrow-band, micromechanical filter whose bandwidth and centre frequency can be adjusted independently. The filter is made of two micro-resonators that are electrostatically coupled using a middle electrode. A low coupling strength results in nearly constant bandwidth while one tunes the centre frequency bi-directionally by applying a DC voltage to the coupling electrode. On the other hand, the bandwidth of the filter is independently modified by applying axial stress to one of the resonators, without affecting the signal attenuation through the filter. Analytic and numerical models for the behaviour of the filter are also presented. Test devices with a centre frequency of about 300 kHz were fabricated in a standard micromachining process. Experimental results support the design principle and validity of the proposed models.

Patent
09 Aug 2012
TL;DR: In this paper, the authors presented a method for detecting input filter capacitor degradation or approach of end of operational life based on filter capacitor current measurements using single and/or dual threshold comparisons for computed instantaneous sum of squares of filter currents or power values.
Abstract: Power conversion systems and methods are presented for detecting input filter capacitor degradation or approach of end of operational life based on filter capacitor current measurements using single and/or dual threshold comparisons for computed instantaneous sum of squares of filter currents or power values.

Patent
27 Sep 2012
TL;DR: In this paper, a feed forward active noise cancellation (ANC) system for use in a portable audio device has an adaptive digital filter and a reference microphone, which is in series with, and in front of, the adaptive filter.
Abstract: A feed forward active noise cancellation (ANC) system for use in a portable audio device has an adaptive digital filter and a reference microphone. A non-adaptive pre-shaping digital filter has an input coupled to the reference microphone and is in series with, and in front of, the adaptive filter. The pre-shaping filter is minimum phase and presents at least 2 dB more gain over a low audio frequency band than over a high audio frequency band. This may help compensate for low frequency band difficulties, and may thereby extend ANC bandwidth at the low end without a worsening impact on the high end. Other embodiments are also described and claimed.

Journal ArticleDOI
TL;DR: In this paper, a voltage mode single-input and four-output multifunction biquadratic filter using single differential voltage current conveyor, three capacitors and two resistors is presented.
Abstract: A new voltage-mode single-input and four-output multifunction biquadratic filter using single differential voltage current conveyor, three capacitors and two resistors is presented. According to the values of the passive components used, the highpass, bandpass, lowpass and notch filters can be simultaneously obtained from the first circuit configuration. Moreover, the allpass, highpass and bandpass filters can be simultaneously obtained from the second circuit configuration. H-Simulation program with integrated circuit emphasis (HSPICE) simulations using Taiwan Semiconductor Manufacturing Company, Ltd. (TSMC) 0.18 µm level 49 complementary metal oxide semiconductor (CMOS) technology process parameters are given to validate theoretical predictions.

Patent
24 Apr 2012
TL;DR: In this paper, the authors proposed a system for coupling a communication unit to an antenna, which includes a tunable bandpass filter and a second tunable filter, such as a low-pass filter, in parallel with the tunable Bandpass filter.
Abstract: A system for coupling a communication unit to an antenna. The system includes a tunable bandpass filter and a second tunable filter, such as a tunable low-pass filter, in parallel with the tunable bandpass filter. The system also includes a measurement and control unit configured to measure a frequency of a signal generated by the communication unit and to tune the tunable bandpass filter to pass the signal generated by the control unit.

01 Apr 2012
TL;DR: In this article, a current-processing cur- rent-controlled universal biquad filter is presented, which employs only two current controlled current conveyor transconductance amplifiers (CCCCTAs) and two grounded capacitors.
Abstract: This paper presents a current-processing cur- rent-controlled universal biquad filter. The proposed filter employs only two current controlled current conveyor transconductance amplifiers (CCCCTAs) and two grounded capacitors. The proposed configuration can be used either as a single input three outputs (SITO) or as three inputs single output (TISO) filter. The circuit realizes all five different standard filter functions i.e. low-pass (LP), band-pass (BP), high-pass (HP), band-reject (BR) and all-pass (AP). The circuit enjoys electronic control of quality factor through the single bias current without dis- turbing pole frequency. Effects of non-idealities are also discussed. The circuit exhibits low active and passive sen- sitivity figures. The validity of proposed filter is verified through computer simulations using PSPICE.

Proceedings ArticleDOI
Reza Sameni1
02 May 2012
TL;DR: A discrete-time linear Kalman filter is presented for removing power-line interference from biomedical recordings and its applications for electrocardiogram and electroencephalogram denoising are presented.
Abstract: A discrete-time linear Kalman filter is presented for removing power-line interference from biomedical recordings. The theoretical aspects of this filter, the relationship with conventional digital IIR and adaptive IIR notch filters, and its steady state behavior are studied in detail. As compared to previous studies, the filter is linear and does not require any information about the amplitude nor the phase of the power-line interference. The proposed method is fairly general and is applicable to broad classes of signals contaminated by periodic noise. The proposed model also accounts for multiple harmonics. Two examples of its applications for electrocardiogram and electroencephalogram denoising are presented.

Journal ArticleDOI
TL;DR: In this article, the authors presented the results of quantitative performance evaluation of an authors' new parabolic sliding mode filter for removing noise from signals in robotics and mechatronics applications, based on the frequency and time domain characteristics.
Abstract: This paper presents the results of quantitative performance evaluation of an authors' new parabolic sliding mode filter, which is for removing noise from signals in robotics and mechatronics applications, based on the frequency and time domain characteristics. Based on the evaluation results, the paper presents selection guidelines of two parameters of the filter. The evaluation results show that, in the frequency domain, the noise removing capability of the filter is almost the same as that of the second-order Butterworth low-pass filter (2-LPF), but its phase lag is smaller (maximum 150 degree) than that of 2-LPF (maximum 180 degree). Moreover, the filter produces smaller phase lag than a conventional parabolic sliding mode filter with appropriate selection of the parameters. In the time domain, the filter produces smaller overshoot than 2-LPF and the conventional one, while maintaining short transient time, by using an appropriately selected parameter. The presented parameter selection guidelines state that the values of the parameters should be chosen according to some estimated characteristics of the input and some desired characteristics of the output. The effectiveness of the filter and the presented guidelines is validated through numerical examples and their application to a closed-loop, force control of a robot manipulator.