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Showing papers on "Electronic filter published in 2002"


Journal ArticleDOI
10 Dec 2002
TL;DR: In this article, a 3.3kV transformerless AC-to-DC power conversion system consisting of a three-phase six-pulse diode rectifier and a shunt hybrid filter is proposed.
Abstract: This paper proposes a 3.3-kV transformerless AC-to-DC power conversion system consisting of a three-phase six-pulse diode rectifier and a shunt hybrid filter. The hybrid filter is formed by a single tuned LC filter per phase and a small-rated three-phase active filter, which are directly connected in series without any matching transformer. The required rating of the active filter is much smaller than that of a conventional standalone active filter be. In addition, no additional switching-ripple filter is required for the hybrid filter because the LC filter functions not only as a harmonic filter tuned at the seventh harmonic frequency but also as a switching-ripple filter around 10 kHz. Experimental results obtained from a 200-V 5-kW laboratory system and simulation results of a 3.3-kV 300-kW system confirm the validity and effectiveness of the system.

235 citations


Patent
22 Jul 2002
TL;DR: A programmable capacitor array including a plurality of user-selectable, numerically weighted capacitors, each of which includes at least one fixed capacitor and one manufacturer-controlled trim capacitor, advantageously provides a variety of selectable capacitance values for a programmable analog integrated circuit as mentioned in this paper.
Abstract: A programmable capacitor array including a plurality of user-selectable, numerically weighted capacitors, each of which includes at least one fixed capacitor and one manufacturer-controlled trim capacitor, advantageously provides a variety of selectable capacitance values for a programmable analog integrated circuit. When coupled to a memory, for example a static memory, switches can be controlled that determine whether a particular fixed capacitor (user-selectable) or trim capacitor (manufacturer-selectable) is electrically coupled into the circuit. User access to those portions of memory controlling switches associated with the trim capacitors can be restricted via an I/O interface and security command. Such programmable capacitor arrays allow efficient implementation of user-programmable filter circuits where the user can conveniently program or reprogram a variety of filter parameters.

94 citations


Patent
15 Feb 2002
TL;DR: In this article, a DC/DC converter apparatus comprising a full bridge non-resonant pulsewidth-modulated (PWM) switching circuit, including inductive device(s), clamp diodes, and an output transformer rectifier and filter circuit is described.
Abstract: Disclosed is a DC/DC converter apparatus comprising a full bridge non-resonant pulse-width-modulated (PWM) switching circuit, which includes inductive device(s), clamp diodes, and an output transformer rectifier and filter circuit. Capacitive and diode elements associated with bridge switching devices operate to switch current through the switches at substantially zero voltage (ZVS). The inductor element and clamp diodes are used to reduce the primary transition shoot through current resulting from reverse recovery of the transformer secondary rectification stage while also reducing emi and semiconductor stresses.

73 citations


Journal ArticleDOI
TL;DR: A new high-speed, programmable FIR filter is presented, which is a multiplierless filter with CSD encoding coefficients, and a new programmableCSD encoding structure is proposed to make CSD coefficients programmable.
Abstract: A new high-speed, programmable FIR filter is presented, which is a multiplierless filter with CSD encoding coefficients. We propose a new programmable CSD encoding structure to make CSD coefficients programmable. Compared with the conventional FIR structure with Booth multipliers, this coding structure improves the speed of filter and decreases the area. We design a 10-bits, 18-taps video luminance filter with the presented filter structure. The completed filter core occupies 6.8 /spl times/ 6.8 mm of silicon area in 0.6 /spl mu/m 2P2M CMOS technology, and its maximum work frequency is 100 MHz.

72 citations


Journal ArticleDOI
TL;DR: In this paper, design techniques for integrated active active LC filters are discussed, including prototype selection, Q enhancement, and automatic tuning, and two designs, both of which are automatically tuned fourth-order bandpass filters in the 2 GHz range, were implemented to demonstrate the proposed techniques and evaluate the potential of such filters.
Abstract: This paper discusses design techniques for integrated active LC filters. Issues related to prototype selection, Q enhancement, and automatic tuning are considered. Two designs, both of which are automatically tuned fourth-order bandpass filters in the 2 GHz range, were implemented to demonstrate the proposed techniques and to evaluate the potential of such filters. Measurement results show that modest dynamic range, suitable for certain stages in transmitter applications, is achieved, along with stable response thanks to the on-chip automatic tuning system.

71 citations


Patent
17 Jan 2002
TL;DR: In this article, the tuning of a filter circuit is accomplished by determining a real RC time constant value for the filter circuit, then comparing the real RC vale to a predetermined RC value.
Abstract: Tuning of a filter circuit is accomplished by determining a real RC time constant value for the filter circuit, then comparing the real RC vale to a predetermined RC value. If the real RC value does not match the predetermined RC value, the real RC value is varied (e.g., using a number of capacitors in a capacitor array).

70 citations


Journal ArticleDOI
TL;DR: In this article, a hybrid active filter topology and its control to suppress the harmonic currents from entering the power source is presented, which consists of one active filter and one passive filter connected in series.

55 citations


Patent
20 Sep 2002
TL;DR: A tunable electrical filter constructed pursuant to the teachings of the present invention includes: (a) a plurality of resonator units coupled between an input locus and an output locus; and (b) a singular tunable dielectric varactor unit coupled between individual varactor units of the plurality of varactors as mentioned in this paper.
Abstract: A tunable electrical filter constructed pursuant to the teachings of the present invention includes: (a) a plurality of resonator units coupled between an input locus and an output locus; and (b) a plurality of tunable dielectric varactor units; respective individual varactor units of the plurality of varactor units being coupled between respective pairs of the plurality of resonator units, coupled between the plurality of resonator units and the input locus, and coupled between the plurality of resonator units and the output locus.

53 citations


Journal ArticleDOI
TL;DR: In this paper, the dependence of receiver sensitivity on the optical filter bandwidth as well as on the bandwidth of the detection electronics for the optical noise limited direct detection case was investigated both experimentally and by means of simulations.
Abstract: In this letter, we investigate both experimentally and by means of simulations, the dependence of receiver sensitivity on the optical filter bandwidth as well as on the bandwidth of the detection electronics for the optical noise limited direct detection case. The experiment is in good agreement with simulations employing advanced Gaussian noise statistics. Bandwidth optimization is performed both for nonreturn-to-zero and return-to-zero coded signals, yielding a measured sensitivity only 1.4 dB off the quantum limit at a data rate of 10 Gb/s.

53 citations


Patent
15 Oct 2002
TL;DR: In this article, a combination of inductors and capacitors is selected through the semiconductor switches so as to maximize a Q factor for the LC filter, where inductors are selectively enabled to configure an LC filter with at least one inductor from each inductive bank and at least two capacitors from each capacitive bank.
Abstract: An inductive (“L”)-capacitive (“C”) filter bank has application for use in a television receiver. The LC filter includes inductors configured in at least one inductive (“L”) bank, and capacitors configured in at least one capacitive (“C”) bank. The inductors and capacitors are selectively enabled so as to configure an LC filter with at least one inductor from the L bank and at least one capacitor from the C bank. A combination of inductors and capacitors are selected through the semiconductor switches so as to maximize a Q factor for the LC filter.

49 citations


Patent
11 Jun 2002
TL;DR: In this article, a filter circuit is formed on a semiconductor substrate formed with a trench (40) that is lined with a dielectric layer (38), a conductive material (37) is disposed in the trench and coupled to a node (62) to provide a capacitance that modifies a frequency response of an input signal (VIN) to produce a filtered signal, and an electrostatic discharge device includes an inductor (74) coupled to back to back diodes (17, 18) formed in the substrate to avalanche when a voltage on the node reaches
Abstract: A filter circuit (10) is formed on a semiconductor substrate (11) formed with a trench (40) that is lined with a dielectric layer (38). A conductive material (37) is disposed in the trench and coupled to a node (62) to provide a capacitance that modifies a frequency response of an input signal (VIN) to produce a filtered signal (VOUT). An electrostatic discharge device includes an inductor (74) coupled to back to back diodes (17, 18) formed in the substrate to avalanche when a voltage on the node reaches a predetermined magnitude.

Patent
20 Nov 2002
TL;DR: In this article, the ON/OFF data inputted from indirect input interface circuits are transmitted to a RAM memory via a variable filter circuit and a two-way serial communication circuit.
Abstract: The invention relates to an on-vehicle electronic controller and intends to lighten the burden on a microprocessor in processing input and output of the controller and miniaturize and standardize the controller. A plurality of ON/OFF data inputted from indirect input interface circuits are transmitted to a RAM memory via a variable filter circuit and a two-way serial communication circuit. A filter constant of the variable filter circuit is set by a constant setting register, and a filter constant stored in the nonvolatile memory is stored in the constant setting register via two-way serial communication circuit.

Patent
02 Apr 2002
TL;DR: In this paper, a fluorescent lamp ballast circuit including a phase cut dimmer connected to a source of AC power, the selectable phase-cut dimmer and an electronic switch having a trigger voltage and a conduction period, when the electronic switch triggers to the end of the half cycle, a rectifying and charging circuit coupled to the output of the phase cut Dimmer for providing a DC voltage across a DC bus, a filter circuit receiving the output from the phase-cuts dimmer, and converting the output to a control signal related to the firing angle of the electronic
Abstract: A fluorescent lamp ballast circuit including a phase cut dimmer connectable to a source of AC power, the selectable phase cut dimmer and an electronic switch having a trigger voltage and a conduction period, when the electronic switch triggers to the end of the half cycle, a rectifying and charging circuit coupled to the output of the phase cut dimmer for providing a DC voltage across a DC bus, a filter circuit receiving the output of said phase cut dimmer and converting the output to a control signal related to the firing angle of the electronic switch; an output stage coupled to the lamp, the output stage having at least one electronic switching device; the ballast control circuit including a control input for changing a frequency of said pulsed power signal, the control input being coupled to said control signal, the control signal varying in accordance with the firing angle of he electronic switch, thereby varying the brightness level of said fluorescent lamp.

Patent
16 Jul 2002
TL;DR: In this paper, an image processing apparatus which can perform motion predicting/compensating operation with a high pixel accuracy and which can have a decreased scale, achieving a low cost and power saving.
Abstract: PROBLEM TO BE SOLVED: To provide an image processing apparatus which can perform motion predicting/compensating operation with a high pixel accuracy and which can have a decreased scale, achieving a low cost and power saving SOLUTION: The apparatus includes a 6-tap filter circuit 42 and a 4-tap filter circuit 43 for generating an interpolating pixel signal for an image signal S40 A selection circuit 44 selects and uses one of 6- and 4-tap filter circuits 42 and 43 on the basis of a block size for motion vector detection in a motion vector generating circuit 46 COPYRIGHT: (C)2004,JPO

Proceedings ArticleDOI
05 Nov 2002
TL;DR: Simulation results using Power System Blockset Toolbox PSB of Matlab show the performance of the series hybrid power filter, and its capability to compensate for voltage type harmonics-producing load.
Abstract: In this paper a series hybrid power filter (SHPF) to compensate harmonic currents and voltages at PCC is proposed The SHPF consists of a small-rated series active power filter (SRSAPF) and a series tuned passive filter (STPF) This combination is suitable for compensating voltage type harmonics-producing load The SHPF uses the synchronous rotating frame method, which detects both source current and load voltage harmonics Simulation results using Power System Blockset Toolbox PSB of Matlab show the performance of the series hybrid power filter, and its capability to compensate for voltage type harmonics-producing load

Patent
18 Nov 2002
TL;DR: In this article, a method of filtering EMI in a power supply includes rectifying an AC signal from an AC source, smoothing the rectified AC signal with a bulk storage capacitor, and filtering the EMI generated by the power conversion circuit from reaching the AC source by using the bulk capacitor and one or more inductors in combination with AC source capacitance as an EMI filter.
Abstract: A power supply electromagnetic interference (EMI) filter circuit and technique In one embodiment, a method of filtering EMI in a power supply includes rectifying an AC signal from an AC source, smoothing the rectified AC signal with a bulk storage capacitor to provide a DC output as an input to a power conversion circuit and filtering the EMI generated by the power conversion circuit from reaching the AC source by using the bulk capacitor and one or more inductors in combination with the AC source capacitance as an EMI filter In one embodiment the method also includes the use of one or more of the inductors as a fusing element

Journal ArticleDOI
TL;DR: In this paper, a second-order bandpass filter is realized by adding a series capacitor to the input port of the gyrator, which can achieve high-Q second-, fourth-and sixth-order fully differential RF bandpass filters operating in the 2.4 GHz Industrial, Scientific and Medical (ISM) frequency band under a 2 V single power supply voltage with low-power dissipation.
Abstract: Based on the gyrator-C inductor topology, a second-order bandpass filter can be realised by adding a series capacitor to the input port of the gyrator. high-Q second-, fourth- and sixth-order fully differential RF bandpass filters operating in the 2.4 GHz Industrial, Scientific and Medical (ISM) frequency band under a 2 V single power supply voltage with low-power dissipation are demonstrated.


Proceedings ArticleDOI
07 Aug 2002
TL;DR: In this article, a hybrid active filter topology and its control to suppress the harmonic currents from entering the power source is presented, which consists of one active filter and one passive filter connected in series.
Abstract: This paper presents a hybrid active filter topology and its control to suppress the harmonic currents from entering the power source. The adopted hybrid active filter consists of one active filter and one passive filter connected in series. By controlling the equivalent output voltage of an active filter, the harmonic currents generated by the nonlinear load are blocked and flow into the passive filter. The power rating of the converter is reduced compared with the pure active filters to filter the harmonic currents. The harmonic current detection approach and DC link voltage regulation are proposed to obtain equivalent voltage of the active filter. The effectiveness of the adopted topology and control scheme has been verified by the computer simulation and experimental results in a scaled-down laboratory prototype.

Proceedings ArticleDOI
07 Nov 2002
TL;DR: In this article, the authors investigated the parallel operation of a current controlled active filter and passive filters in a system with current harmonic sources, where the task of reactive power and harmonic compensation is shared by the active filters and the passive filters.
Abstract: This paper reports investigations of the parallel operations of a current controlled active filter and passive filters in a system with current harmonic sources. The task of reactive power and harmonic compensation is shared by the active filter and passive filters. The passive filters are used for supplying reactive power to the connected AC system and eliminating some harmonics, the active filter is used to cancel out the other harmonics. This can be achieved by taking the suitable reference current of the active filter and signal processing filters in the control loop. In parallel combination arrangements of the active and passive filters can operate relatively independently, also the compensation flexibility of the active filter can be fully exploited, such as one active filter for several harmonic sources. The simulation studies on various systems have been performed to evaluate the effectiveness of the systems. The results show that the power factor is corrected by the passive filters, harmonics are minimized by both active and passive filters and overloading of the filter system can be avoided.

Journal ArticleDOI
TL;DR: In this article, two-pole and four-pole passband filters in 900 MHz frequency band using novel square microstrip resonators are presented, and measured filters' responses demonstrate the feasibility of selective filters using these new resonators.
Abstract: Compact two-pole and four-pole passband filters in 900 MHz frequency band using novel square microstrip resonators are presented. The measured filters' responses demonstrate the feasibility of selective filters using these new resonators.

Patent
04 Jun 2002
TL;DR: In this article, the authors proposed a multi-band communication system with a first filter circuit for passing a transmission signal of a transmission/reception system of the CDMA system emitted from a first antenna.
Abstract: PROBLEM TO BE SOLVED: To provide a RF circuit for a multi-band communication system and a multi-band antenna switch module optimum to a mobile phone adopting the combination of the CDMA system and the TDMA system. SOLUTION: The RF circuit for a multi-band communication system is provided with: a first filter circuit for passing a transmission signal of a transmission / reception system of the CDMA system emitted from a first antenna; a CDMA transmission section connected to the first filter circuit; a second filter circuit for passing a transmission / reception signal of a transmission / reception system of the first TDMA system emitted from the first antenna; a first switch circuit connected to the second filter circuit and for selecting the signal path of the transmission signal of the transmission system of the first TDMA system or the signal path of the reception signal of the transmission / reception system of the first TDMA system; a first TDMA transmission section connected to the first switch circuit; a first TDMA reception system connected to the first switch circuit; a third filter circuit for passing a reception signal of the transmission / reception system of the CDMA system emitted from the second antenna; and a CDMA reception section placed at the post-stage of the third filter circuit. COPYRIGHT: (C)2004,JPO

Patent
15 Oct 2002
TL;DR: In this paper, a functional comparator is used to compare offset, capacitive, inductive and frequency values to tune the LC filter for operation in the VHF and UHF bands.
Abstract: A receiver, such as a television receiver, tunes an inductive (“L”) and capacitive (“C”) filter based on a desired frequency. The LC filter includes a plurality of inductors, configured in at least one inductive (“L”) bank, and a plurality of capacitors configured in at least one capacitive (“C”) bank. The inductors are selectively enabled for the LC filter by an N code, and the capacitors are selectively enabled for the LC filter by an M code. The receiver uses a functional comparator to compare offset, capacitive, inductive and frequency values to tune the LC filter. Techniques for tuning the LC filter for operation in the VHF and UHF bands are disclosed.

Patent
06 Aug 2002
TL;DR: In this paper, a switching power unit is a PWM system in which, in response to a secondary-side output voltage detected by an output voltage detecting circuit, a control circuit controls a duty of a main switching element so as to stabilize the output voltage.
Abstract: The switching power unit is a switching power unit of PWM system in which, in response to a secondary-side output voltage detected by an output voltage detecting circuit, a control circuit controls a duty of a main switching element so as to stabilize the output voltage. There is provided a filter circuit, preventing EMI, which is constituted of filter capacitors and a filter coil. In relation to the filter circuit, there is provided a discharging resistor which is constituted of two series resistors so as to prevent an accident by discharging electric charges of the filter capacitors quickly. A voltage of a connection point between the series resistors is applied to a power supplying capacitor of the control circuit via an activating resistor. Thus, when a power source is turned on, an activating current is supplied from a voltage whose value is ½ with respect to a root means square value of a rough input ac voltage, so that it is possible to reduce a loss in an activating circuit which activates the control circuit.

Patent
18 Mar 2002
TL;DR: In this article, a high-pass filter has a serial resonance circuit composed of an inductor L1 connected between an input terminal P1 and the ground, a capacitor C 1 connected between the output terminal P2 and a capacitance C 2 connected between L1 and ground.
Abstract: PROBLEM TO BE SOLVED: To provide an electrostatic surge measure circuit for protecting a high frequency component such as high frequency switch or SAW filter from electrostatic surge, and an antenna switch module in which measures are taken to cope with the electrostatic surge. SOLUTION: The high-pass filter has a serial resonance circuit composed of an inductor L1 connected between an input terminal P1 and the ground, a capacitor C1 connected between the input terminal P1 and an output terminal P2, an inductor L2 connected to the output terminal P2 and a capacitor C2 connected between the inductor L2 and the ground. Besides, in the multi-band antenna switch circuit and the multi-band antenna switch lamination module, such a high-pass filter to cope with the electrostatic surge is incorporated. COPYRIGHT: (C)2003,JPO

Proceedings ArticleDOI
02 Jun 2002
TL;DR: In this article, the design and realization of a new class of miniaturized microstrip filters using folded quarter-wave resonators is presented, and the design rules for cross-coupled filters with quasi-elliptical function and flat group delay response are provided.
Abstract: This paper presents the design and realization of a new class of miniaturized microstrip filters using folded quarter-wave resonators Various kinds of filter response are realized by proper arrangement of the resonator The design rules for cross-coupled filters with quasi-elliptical function and flat group delay response are provided The measured results match theoretical predictions well

Patent
14 Jan 2002
TL;DR: In this paper, an active common-mode EMI filter was proposed, which is capable of using low-voltage amplifier devices by using a separate amplifier dc source unrelated to the system operating voltage and also was capable of circulating the leakage current within the system by coupling capacitors.
Abstract: The present invention relates to an active common-mode EMI filter which is capable of using low-voltage amplifier devices by using a separate amplifier dc source unrelated to the system operating voltage and also is capable of circulating the leakage current within the system by coupling capacitors that operate for the filter circuit to be separated at low frequency and form the closed circuit with the main circuit of the system at high frequency. As a result, it is possible to use fast active devices than the filter circuit of prior arts regardless of the operating voltage of the target system. The present invention can solve the prior art's problem that transistors with higher voltage rating should be used in order for bipolar transistors to withstand the total dc voltage of the system while using a method for detecting and compensating the high-frequency common-mode current.

Patent
25 Mar 2002
TL;DR: In this paper, an active reception antenna comprised of a passive antenna component with a frequency-dependent effective length was proposed. But the active reception antennas were not considered in this paper.
Abstract: The invention relates to an active reception antenna comprised of a passive antenna component with a frequency-dependent effective length l e . The output connections of this passive component are connected to the input connections of an amplifier circuit. The amplifier circuit consists of a field effect transistor and a low-loss filter circuit with an input admittance. The low-loss filter circuit is connected on its input to the source connection of the field effect transistor. On its output, the high-frequency reception signal is de-coupled, and the low-loss filter circuit is loaded with an effective resistance or conductance acting on its output. The blind or dummy elements of the low-loss filter circuit are selected so that the frequency dependence of the real component G of the input admittance acting on the input of the low-loss filter circuit is adjusted so that with the specified reception capacity, the frequency curve conditioned by the frequency-dependent effective length l e of the passive antenna component is realized within a broad frequency band under freely selected aspects. The amount of input admittance effectively acting on the input of the low-loss filter circuit is adequately low outside of the frequency band so as to avoid non-linear effects in the blocked frequency range.

Patent
16 Oct 2002
TL;DR: In this paper, a trap inductor and high-pass filter inductors have axes which extend substantially perpendicularly to the planes of the insulating sheets, and each of the inductors defines, in combination with a highpass circuit inductor, a trap circuit.
Abstract: An LC high-pass filter circuit device includes an inductor defined by via holes formed in adjacent insulating sheets which are connected in the direction of stacking of the sheets so as to define a single trap inductor. Inductor via holes formed in another insulating sheet define separate high-pass filter inductors. The trap inductor and the high-pass filter inductors have axes which extend substantially perpendicularly to the planes of the insulating sheets. Each of the high-pass circuit inductors defines, in combination with a high-pass filter capacitor, a high-pass filter circuit, while the trap inductor defines, in combination with a capacitor, a trap circuit. The high-pass filter circuits and the trap circuit in combination define a small-sized LC high-pass filter circuit device which exhibits high Q value and which excels in frequency characteristics, as well as a laminated LC high-pass filter device, a multiplexer and a radio communication apparatus incorporating the LC high-pass filter circuit device.

Proceedings ArticleDOI
24 Oct 2002
TL;DR: In this article, the use of low-cost active circuitry to suppress motor drive emissions, thus reducing passive filtration requirements, is explored, and a voltage sense, current drive active filter is developed that greatly enhances the performance of filter capacitors.
Abstract: EM1 filters for automotive motor drives must achieve stringent EM1 specifications while meeting tight cost constraints. This paper explores the use of low-cost active circuitry to suppress motor drive emissions, thus reducing passive filtration requirements. Challenges to the use of active EM1 filters in this application are outlined, and means for addressing these challenges are presented. A voltage sense, current drive active filter is developed that greatly enhances the performance of filter capacitors. The proposed approach is applied to an input filter for an automotive electro-hydraulic power steering pump drive. Experimental results are presented that demonstrate the feasibility and high performance of this approach and illustrate its advantages over conventional filter designs.