Phase Shift Type Patents (Class 331/135)
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Patent number: 7863990Abstract: Provided is an oscillation circuit for generating an oscillation signal synchronized with a supplied reference clock, including: a voltage control oscillation section that, when triggered by each edge of the reference clock, stops oscillation of the oscillation signal having a frequency in accordance with a supplied control voltage to start new oscillation; a phase comparing section that compares a phase of a comparison signal that is in accordance with the oscillation signal outputted from the voltage control oscillation section and a phase of a signal that is in accordance with the reference clock; and a voltage control section that supplies the control voltage in accordance with a comparison result of the phase comparing section, to the voltage control oscillation section.Type: GrantFiled: June 9, 2008Date of Patent: January 4, 2011Assignee: Advantest CorporationInventor: Masakatsu Suda
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Patent number: 7847643Abstract: In an embodiment, a circuit is provided comprising a multi-phase oscillator configured to output a plurality of output signals having the same frequency and different phase offsets. A feedback value is generated based on at least two of said output signals. A reference value is generated based on a reference clock and a predetermined value. The reference value and the feedback value are combined.Type: GrantFiled: November 7, 2008Date of Patent: December 7, 2010Assignee: Infineon Technologies AGInventor: Nicola Da Dalt
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Patent number: 7825741Abstract: A method of generating an output signal from an input signal includes a step of generating a set of n signals, n being an integer greater than or equal to 3, by generating a signal for each integer i such that 0?i?(n?1), each signal within the set having the same frequency and approximately equal amplitude and a phase equal to (360/n)i degrees. The method also includes a step of inputting each of the set of n signals to a gate terminal of a corresponding one of a set of n transistors. Each of the transistors has a source terminal electrically connected to a common voltage drain and each of the transistors has a drain terminal electrically connected to a coupling. The coupling is electrically connected to a common voltage source. The output signal at the coupling has a frequency equal to the frequency of the input signal multiplied by n.Type: GrantFiled: May 27, 2008Date of Patent: November 2, 2010Assignee: International Business Machines CorporationInventors: Scott Kevin Reynolds, Mehmet Soyuer, Chinmaya Mishra
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Publication number: 20100237958Abstract: Systems, methods, and apparatus are described that provide for low phase-noise, spectrally-pure, and low-jitter signals from electrical oscillators. An aspect of the present disclosure includes utilization of an open-loop feed-forward phase-noise cancellation scheme to cancel phase noise, or jitter, of an electrical oscillator. Phase noise can be measured and then subtracted, with the phase noise measurement and subtraction being performed at a speed faster than phase noise variations of the oscillator. Another aspect of the present disclosure includes use of a feedback scheme for phase noise reduction. A feedback scheme can be used alone or in conjunction with a feed-forward scheme. Related phase-noise cancellation and/or reduction methods are described. Notch filter and RF amplifier circuits are also described.Type: ApplicationFiled: March 18, 2010Publication date: September 23, 2010Applicant: UNIVERSITY OF SOUTHERN CALIFORNIAInventors: Ankush Goel, Alireza Imani, Hossein Hashemi
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Patent number: 7741920Abstract: An oscillator circuit providing quadrature outputs and enabling instantaneous control over phase, frequency and amplitude of the output waveforms is disclosed. In one embodiment, the oscillator circuit comprises an oscillation loop, at least one capacitor switching circuit coupled to the oscillation loop, and a synchronization signal having an output coupled to the at least one capacitor switching circuit. The synchronization signal may be derived internally from the oscillation loop or externally from an external oscillator.Type: GrantFiled: February 10, 2006Date of Patent: June 22, 2010Assignee: Broadcom CorporationInventor: Jan R. Westra
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Patent number: 7705685Abstract: An oscillator operates at a very low voltage yet has a duty cycle that is set by a ratio of capacitors that are charged and discharged. Sub-threshold p-channel transistors conduct sub-threshold currents below the normal threshold voltage, and drive set and reset inputs of a set-reset S-R latch. The S-R latch drives the oscillator outputs. The oscillator outputs feed back to charging p-channel transistors that charge one plate of the capacitors. During half of the cycle, the charging p-channel transistor is off, allowing one plate of the capacitors to discharge through an n-channel discharge transistor. After a period of discharge determined by the capacitance of the capacitor, the gate of a sub-threshold p-channel transistor falls enough for sub-threshold current to flow, triggering the set or reset input of the S-R latch. Since sub-threshold currents are needed to toggle the S-R latch, the oscillator begins to oscillate below the threshold voltage.Type: GrantFiled: December 6, 2007Date of Patent: April 27, 2010Assignee: Hong Kong Applied Science and Technology Research Institute Co., Ltd.Inventors: Chik Wai David Ng, Yat To William Wong, Ho Ming Karen Wan, Kwok Kuen David Kwong
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Patent number: 7687703Abstract: This disclosure describes techniques for generating a set of data points that form a triangular wave having a desired gain and a desired frequency. In one example, the method includes the step of (a) determining an increment value based on the desired frequency and the desired gain of the triangular wave. The method further includes the step of (b) adding the increment value to a current data point to generate a next data point, the current data point and the next data point forming a subset of the set of data points. The method further includes the step of iteratively performing (a) and (b) to generate the set of data points that form the triangular wave.Type: GrantFiled: March 4, 2008Date of Patent: March 30, 2010Assignee: QUALCOMM IncorporatedInventors: Stephen Molloy, Suresh Devalapalli, Nidish Ramachandra Kamath
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Patent number: 7659783Abstract: A phase-locked loop (PLL) to provide clock generation for high-speed memory interface is presented as the innovate PLL (IPLL). The IPLL architecture is able to tolerate external long loop delay without deteriorating jitter performance. The IPLL comprises in part a common mode feedback circuit with a current mode approach, so as to minimize the effects of mismatch in charge-pump circuit, for instance. The voltage-controlled oscillator (VCO) of the IPLL is designed using a mutually interpolating technique generating a 50% duty clock output, beneficial to high-speed double data rate applications. The IPLL further comprises loop filter voltages that are directly connected to each VCO cell of the IPLL. Conventional voltage-to-current (V-I) converter between loop filter and VCO is hence not required. A tight distribution of VCO gain curves is therefore obtained for the present invention across process corners and varied temperatures.Type: GrantFiled: July 16, 2007Date of Patent: February 9, 2010Assignee: Micrel, Inc.Inventor: Gwo-Chung Tai
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Patent number: 7629858Abstract: One aspect relates to an oscillator, and various oscillator embodiments comprise an amplifier and line driver with an input and an output and a transmission line with a predetermined transmission signal time delay. The output is adapted to produce an inverted signal with respect to a signal received at the input. The transmission line has a first end connected to the output and a second end connected to the input. Other aspects and embodiments are provided herein.Type: GrantFiled: September 13, 2007Date of Patent: December 8, 2009Assignee: Micron Technology, Inc.Inventors: Leonard Forbes, David R. Cuthbert
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Publication number: 20090115541Abstract: The present invention pertains to a circuit comprising a DC current source and at least two spin torque oscillators, the at least two spin torque oscillators being electrically coupled to each other and to the DC current source. A circuit comprising phase shifting means is connected in such a way as to cause a phase shift between current and voltage through the spin torque oscillators. An advantage of the present invention is that the controlled phase shift significantly increases the tolerance for deviating anisotropy fields, which makes manufacturing of spin torque oscillator devices much more feasible in practice. FIG. 2, wherein the DC current source comprises phase shifting means.Type: ApplicationFiled: October 31, 2008Publication date: May 7, 2009Inventors: Johan Persson, Yan Zhou, Johan Akerman
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Patent number: 7486151Abstract: In a timer circuit of a semiconductor circuit including a current source driven by a power supply voltage, the current source outputs a current dependent on the power supply voltage, and outputs a reference voltage obtained when the power supply voltage is dropped by a predetermined drop voltage. A capacitor is charged with electric charges by the current outputted from the current source. The comparator compares a voltage across the capacitor with the reference voltage from the current source, and outputs an output signal when a voltage across the capacitor is equal to or higher than the reference voltage. The timer circuit outputs an output signal after a delay time, from a timing when supply of the power supply voltage is started, to a timing when the voltage across the capacitor rises substantially in proportion to an elapsed time by charging the capacitor and reaches the reference voltage.Type: GrantFiled: October 28, 2005Date of Patent: February 3, 2009Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Shinsuke Goudo
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Patent number: 7474162Abstract: An RC oscillator circuit is disclosed. The RC oscillator circuit includes a current generator configured to generate a charge current. The RC oscillator circuit also includes an integrator having an input and an output, the input being connected to the current generator. The RC oscillator circuit also includes a comparator having a first input, a second input, and an output, the first input being connected to the output of the integrator and the second input being configured to supply a reference threshold. The RC oscillator circuit also includes a clock pulse generator connected to the output of the comparator and a reference generator configured to generate the reference threshold based on a supply voltage of the RC oscillator circuit.Type: GrantFiled: August 24, 2004Date of Patent: January 6, 2009Assignee: Austriamicrosystems AGInventors: Paolo D'Abramo, Riccardo Serventi
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Patent number: 7414482Abstract: A resonator-synchronized oscillator for resonance mode selection is disclosed. In one embodiment, the resonator-synchronized oscillator comprises an oscillation loop, at least one capacitor switching circuit coupled to the oscillation loop, and a multi-mode resonator having an output coupled to the at least one capacitor switching circuit. The output signal of the resonator is used to synchronize the oscillator using switched capacitor structures to instantaneously reset the phase of the resonator-synchronized oscillator.Type: GrantFiled: February 10, 2006Date of Patent: August 19, 2008Assignee: Broadcom CorporationInventor: Jan R. Westra
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Patent number: 7411466Abstract: An overtone crystal oscillator including a crystal, multiple amplifiers and an RC network. The crystal has a fundamental resonance frequency and at least one overtone resonance frequency. The amplifiers are coupled in series between terminals of the crystal and the RC network is coupled to the amplifiers. The amplifiers and the RC network are collectively configured to suppress oscillation of the crystal at the fundamental resonance frequency and to enable oscillation at an overtone resonance frequency of the crystal. The amplifiers and the RC network may be configured to cause a phase shift between the fundamental resonance frequency and the overtone resonance frequency. The overtone resonance frequency may be any odd harmonic of the fundamental frequency, such as a third overtone of the crystal. The overtone crystal oscillator may be integrated with CMOS processes and does not require an inductor to suppress the fundamental mode of oscillation.Type: GrantFiled: July 14, 2006Date of Patent: August 12, 2008Assignee: Freescale Semiconductor, Inc.Inventor: Ronald C. Alford
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Patent number: 7397316Abstract: A ring oscillator and a phase error calibration method are provided. The ring oscillator may include a first voltage-current converter for controlling and outputting an amount of tail current Itail according to a magnitude of a first control voltage applied in feedback in a PLL circuit; a second voltage-current converter for controlling and outputting an amount of shift current according to a magnitude of a second control voltage applied from a system phase error detector; and differential amplifiers for controlling, for output signals, a delay time of signals based on the applied tail current amount and a shift time of the signals based on the shift current amount. Thus, a phase relation between in-phase and quadrature-phase signals outputted from the ring oscillator may be controlled.Type: GrantFiled: January 31, 2006Date of Patent: July 8, 2008Assignee: Samsung Electronics Co., Ltd.Inventors: Hyun-su Chae, Hoon-tae Kim, Jung-eun Lee
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Patent number: 7391840Abstract: A phase locked loop (PLL) circuit (1) comprising a loop input (11); a phase detector section (2) for detecting a phase difference between an input signal and a reference signal. The phase detector section (2) has a detector input connected to the loop input, a reference input and a detector output for outputting a signal related to the phase difference. A controlled oscillator (4) is connected with an input to the detector output and an oscillator output is connected to a loop output (12). The PLL has a feedback circuit which connects the oscillator output to the reference input, wherein the feedback circuit includes a device (7;71-74) having a transfer function with at least one zero.Type: GrantFiled: July 3, 2002Date of Patent: June 24, 2008Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventor: Johannes Wilhelmus Theodorus Eikenbroek
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Patent number: 7375600Abstract: An integrated quartz oscillator circuit is disclosed having a capacitive voltage divider, which has a first capacitor and a second capacitor, as well as having a first transconductance amplifier, which is placed in a loop connecting a first terminal and a second terminal of the first capacitor. An input of the first transconductance amplifier is connected to a center tap between the first capacitor and the second capacitor, an output of the first transconductance amplifier is connected to the first junction of the first capacitor, and the quartz oscillator circuit has a conductive element connected parallel to the second capacitor.Type: GrantFiled: July 10, 2006Date of Patent: May 20, 2008Assignee: Atmel Germany GmbHInventor: Udo Karthaus
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Patent number: 7356719Abstract: In an EEPROM of a microcomputer, data is stored for determining a communication rate CMR for fixing the data transmission time of one frame managed by a communication circuit on the basis of an oscillation output characteristic of a CR oscillating circuit that varies in accordance with temperature. CPU reads out data stored in EEPROM in accordance with the temperature detected by a temperature detecting circuit, and sets the determined communication CMR into the communication circuit.Type: GrantFiled: February 21, 2006Date of Patent: April 8, 2008Assignee: DENSO CORPORATIONInventors: Toshihiko Matsuoka, Hideaki Ishihara, Yukari Sugiura
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Patent number: 7339442Abstract: An apparatus and method are provided for tracking the poles of an integrated RC filter as well as the absolute value of a current source. A single tracking oscillator contains integrated elements such as a programmable resistor and fixed capacitor or a programmable capacitor and fixed resistor. The programmable element is programmed such that a particular response from the RC filter is achieved and the word used to program the programmable element is then supplied to other integrated RC filters having components that were fabricated at the same time as the RC filter in the tracking oscillator. A highly accurate external capacitor or resistor is supplied to determinate the absolute value of the programming element, which is used to program one or more current sources containing the programmable resistor.Type: GrantFiled: July 7, 2005Date of Patent: March 4, 2008Assignee: Freescale Semiconductor, Inc.Inventor: Nihal J. Godambe
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Patent number: 7336135Abstract: An oscillator for ensuring the phase relationship between two resonant circuits coupled by a coupling circuit. A first resonant circuit outputs two signals having different phases, and a second resonant circuit outputs two signals having different phases. The coupling circuit includes a plurality of inverters connected in a ring manner, and couples the first resonant circuit and the second resonant circuit such that the two signals output from the first resonant circuit and the two signals output from the second resonant circuit have different phases. A filter is connected to the input side of each of the plurality of inverters. With this structure, a signal output from each of the plurality of inverters has either a phase lead or a phase lag according to the phase characteristics of the corresponding filter, and thus the phase relationship between the first resonant circuit and the second resonant circuit is ensured.Type: GrantFiled: December 30, 2004Date of Patent: February 26, 2008Assignee: Fujitsu LimitedInventors: Hirohito Higashi, Hideki Ishida
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Patent number: 7315220Abstract: A voltage controlled oscillator (VCO) having a single stage ring-oscillator having both coarse and fine control of the frequency of oscillation is described. In an embodiment the VCO may include a first n-channel latch having a first output and a second output; a first P-channel transistor coupled between a voltage supply and a first VCO output, where a gate of the first P-channel transistor is coupled to the first output of the first n-channel latch; a first programmable resistor circuit coupled between the first VCO output and the first output of the first n-channel latch; and a second n-channel latch coupled to the first VCO output.Type: GrantFiled: January 27, 2006Date of Patent: January 1, 2008Assignee: Xilinx, Inc.Inventors: Moises E. Robinson, Shahriar Rokhsaz, Marwan M. Hassoun, Earl E. Swartzlander, Jr.
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Publication number: 20070285185Abstract: There is disclosed a self-calibrating resistor-capacitor (RC) oscillator in which a resistor has a resistance value varied minimally by temperature change and process variation, a capacitor has a capacitance value selected adequately according to needs, and the resistor and capacitor are configurable as a one-chip by a complementary metal-oxide semiconductor (CMOS) process. The self-calibrating RC oscillator comprises a resistor part including a first resistor having a resistance value reduced with increase in temperature and a second resistor connected in series with the first resistor and having a resistance value increasing with increase in temperature.Type: ApplicationFiled: May 25, 2007Publication date: December 13, 2007Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.Inventors: Yong Il KWON, Tah Joon PARK
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Patent number: 7295081Abstract: One aspect relates to an oscillator, and various oscillator embodiments comprise an amplifier and line driver with an input and an output and a transmission line with a predetermined transmission signal time delay. The output is adapted to produce an inverted signal with respect to a signal received at the input. The transmission line has a first end connected to the output and a second end connected to the input. Other aspects and embodiments are provided herein.Type: GrantFiled: August 29, 2005Date of Patent: November 13, 2007Assignee: Micron Technology, Inc.Inventors: Leonard Forbes, David R. Cuthbert
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Patent number: 7286022Abstract: There is provided a resistor-capacitor (RC) oscillator circuit insensitive to process, voltage, and temperature variances. The RC oscillator circuit includes a delay unit, a resistor unit, a capacitor, a resistor, and a first controller. The delay unit delays and outputs a signal received through an input terminal. The resistor unit is connected between an input terminal of the delay unit and a first node. The capacitor is connected between an output terminal of the delay unit and the first node. The resistor is connected between the input terminal of the delay unit and an output node. The first controller is connected between the output terminal of the delay unit and the output node, wherein a frequency signal is output through the output node.Type: GrantFiled: February 11, 2006Date of Patent: October 23, 2007Assignee: Samsung Electronics Co., Ltd.Inventors: Chang-Hyon Park, Hong-Keun Yune
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Patent number: 7271670Abstract: A CR oscillation circuit comprises first and second logic elements, a capacitive element, and a resistive element. The first logic element is connected between a first node and a second node. The second logic element is connected between the second node and a third node. The capacitive element is connected between the first node and the second node. The resistive element is connected between the first node and the third node. The capacitive element includes a well, a diffusion layer, a gate electrode and a gate oxide film. The capacitive element has a voltage-dependence characteristic such that its capacitance value varies according to the variation in a supply voltage. The capacitance value of the capacitive element decreases when the on-resistance of the first and second logic elements increases according to the variation in the supply voltage.Type: GrantFiled: November 10, 2005Date of Patent: September 18, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Kazuyoshi Nishi, Junji Takiguchi
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Publication number: 20070205838Abstract: An oscillator coupling system includes a plurality of oscillating members and a plurality of delay members connecting at least two of the oscillating members. Between the delay members is a specific phase or time delay relationship such that characteristics of phase or frequency noise suppression correlation of the two oscillating members are coupled to each other by the delay members, thereby reducing noise autocorrelation while the oscillator coupling system is in operation, enhancing phase or frequency noise suppression, using no bulky elements such as solid state circulators, isolators and resonators, reducing signal distortion, and increasing system stability.Type: ApplicationFiled: December 21, 2006Publication date: September 6, 2007Inventor: Heng-Chia Chang
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Publication number: 20070182499Abstract: A first comparator outputs a first signal indicative that a voltage determined according to the amount of charge stored in a first capacitor has reached a first reference voltage. A second comparator outputs a second signal indicative that a voltage determined according to the amount of charge stored in a second capacitor has reached a second reference voltage. An RS flip flop circuit is shifted to a set state by one of the first signal and the second signal and shifted to a reset state by the other signal. When the RS flip flop circuit is in the set state, the first capacitor is in a charge state, and the second capacitor is in a discharge state. When the RS flip flop circuit is in the reset state, the first capacitor is in a discharge state, and the second capacitor is in a charge state.Type: ApplicationFiled: February 8, 2007Publication date: August 9, 2007Inventors: Katsushi Wakai, Ichiro Yamane, Toshifumi Hamaguchi, Kazuhisa Raita
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Patent number: 7205857Abstract: An oscillator that provides a quadrature output and has a cross-coupled configuration is disclosed. The oscillator generates an output signal having a frequency. Two phase shift circuits, or stages, are activated by a control signal to provide phase shifts within the oscillator. Each phase shift circuit includes poles to provide the phase shift. A pole includes a varactor to tune, adjust or vary the phase shift accordingly.Type: GrantFiled: September 15, 2005Date of Patent: April 17, 2007Assignee: Broadcom CorporationInventor: Hung-Ming Chien
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Patent number: 7202753Abstract: An power divider and a surface acoustic wave resonator are provided to a feedback path of an amplifier for oscillation. The surface acoustic wave resonator connects an input side of the amplifier and the power divider connects an output side of the amplifier so as to suppress an input power input to the surface acoustic wave resonator and to secure an output power output from an output terminal of the power divider.Type: GrantFiled: July 29, 2004Date of Patent: April 10, 2007Assignee: Seiko Epson CorporationInventor: Yutaka Takada
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Patent number: 7199676Abstract: A frequency adjustment circuit that maintains a target frequency even when frequency adjustment data of zapping circuit is changed by an external noise is offered. The frequency adjustment circuit includes a reset signal generation circuit, a frequency adjustment data latch circuit that latches and retains the frequency adjustment data ZP1 and ZP2 generated by a first zapping circuit and a second zapping circuit based on a latch clock ZCLK and a latch clock generation circuit that generates the latch clock ZCLK. The reset signal generation circuit generates a periodic reset signal ZRES that is synchronized with a rise of an enable signal EN generated from an interface circuit. The latch clock generation circuit generates the latch clock ZCLK that is synchronized with a fall of the enable signal EN.Type: GrantFiled: August 4, 2005Date of Patent: April 3, 2007Assignee: Sanyo Electric Co., Ltd.Inventors: Tetsuya Tokunaga, Hiroyuki Arai, Takeshi Kimura, Ryouichi Ando, Mamoru Yamaguchi
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Patent number: 7170357Abstract: A crystal oscillator having a crystal filter with multiple crystals in a ladder configuration, resonant at a desired operating frequency. An oscillatory signal loop feedback path includes a voltage controlled phase shifter operable to shift the phase of the signal in the feedback loop in response to an applied control voltage. The feedback loop also includes a loop phase shift circuit to ensure that the feedback signal is a multiple of 360°, and a band pass mode selection circuit for eliminating unwanted frequencies.Type: GrantFiled: March 4, 2005Date of Patent: January 30, 2007Assignee: Northrop Grumman CorporationInventors: Michael M. Driscoll, Karl M. Metzger, Christopher R. Vale, Norman G. Matthews
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Patent number: 7161439Abstract: According to some embodiments, a circuit includes a ring oscillator delay stage. The delay stage may include a first transistor, a second transistor, and an active inductor. A gate of the first transistor may receive a first input signal, a gate of the second transistor may receive a second input signal, a source of the second transistor may be coupled to a source of the first transistor, and the active inductor may be coupled to a drain of the first transistor.Type: GrantFiled: November 18, 2004Date of Patent: January 9, 2007Assignee: Intel CorporationInventors: Fabrice Paillet, Tanay Karnik, Jianping Xu
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Patent number: 7157982Abstract: In a Wien-Robinson oscillator, a negative feedback path and a positive feedback path are arranged between the output of an operational amplifier and a reference ground potential. The negative feedback path contains two resistors which are connected in series and whose common circuit point is connected to the inverting input of the operational amplifier. The positive feedback path is formed from two RC elements which are connected in series and whose common circuit point is connected to the non-inverting input of the operational amplifier. If the aim is to keep the amplitude of the output voltage from the oscillator constant, additional measures are required, which increase the circuitry complexity. In order to stabilize the output voltage from the oscillator with little complexity, a third resistor is arranged between the output of the operational amplifier and that end of the positive feedback path which faces away from the reference ground potential.Type: GrantFiled: June 18, 2003Date of Patent: January 2, 2007Assignee: Bosch Rexroth AGInventor: Karlheinz Panzer
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Patent number: 7151415Abstract: An injection locked dual opto-electronic oscillator having a master oscillator which generates a high Q RF output signal with a plurality of harmonic signals within a predetermined pass band. A slave oscillator has a modulation input coupled to the output signal from the master oscillator as well as an output signal. The slave oscillator has a cavity length selected to produce a single mode operation within the pass band. An electronic phase shifter in the slave oscillator is adjustable to produce constructive interference at a single harmonic of the output signal from the master oscillator and destructive interference of all other harmonics within the pass band and to bring the slave oscillator into injection locked condition with the master oscillator. Therefore the slave OEO is used as a filter for the spurious radiation generated by the master OEO and at the same time preserves the high Q of the RF carrier signal from the master OEO.Type: GrantFiled: February 1, 2005Date of Patent: December 19, 2006Assignee: The United States of America as represented by the Secretary of the ArmyInventor: Weimin Zhou
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Patent number: 7146140Abstract: Briefly, exemplary embodiments of the invention may provide devices and methods to provide precise and/or low phase-noise quadrature oscillation signals. A quadrature oscillator in accordance with an exemplary embodiment of the invention may include, for example, a phase-shift generator to provide a phase-shift of substantially ?/2 radians to an oscillation signal between a first oscillation tank, which provides substantially no phase-shift, and a second oscillation tank.Type: GrantFiled: June 30, 2003Date of Patent: December 5, 2006Assignee: Intel CorporationInventors: Ashoke Ravi, Krishnamurthy Soumyanath
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Patent number: 7129798Abstract: An oscillator includes first, second and third inverters (1, 2, 3) connected in series. A feedback path is connected from the output terminal of the third inverter (3) to the input terminal of the first inverter 1 through a resistor (5) while a second feedback path is connected from the output terminal of the second inverter (2) to the input terminal of the first inverter (1) through a capacitor (4). The second feedback path further includes a resistor (6) having a temperature coefficient larger than that of resistor (5) is inserted to adjust the charge/discharge trigger voltage and charge/discharge time of the capacitor (4).Type: GrantFiled: October 6, 2003Date of Patent: October 31, 2006Assignee: Denso CorporationInventors: Seiki Aoyama, Toshikazu Itakura
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Patent number: 7053723Abstract: The present invention proposes a new way of improving the phase stability and frequency selectivity of a phase shift oscillator (100). By introducing a filter-order enhancing feedback loop (124) in association with a phase shift filter (122) in the oscillator, higher-order phase shift filtering can be achieved without using inductive elements as in conventional higher-order LC phase shift filters. This is a great advantage, since a high Q-value can be obtained without limited by the relatively high internal losses of inductive elements (L).Type: GrantFiled: June 20, 2001Date of Patent: May 30, 2006Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventor: Jesper Fredriksson
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Patent number: 7046096Abstract: An oscillator circuit is a closed loop including an amplifying circuit and a feedback circuit. The amplifying circuit includes a pair of amplifiers, which also function as impedance buffers, and a first phase-shift circuit. The feedback circuit includes a second phase-shift circuit and a piezoelectric vibrator. The second phase-shift circuit is capable of adjusting the phase and gain of the feedback circuit. The first phase-shift circuit of the amplifying circuit is arranged between the pair of amplifiers and is separated, in terms of impedance, from the second phase-shift circuit. The first phase-shift circuit is capable of adjusting the phase of the entire closed loop.Type: GrantFiled: March 15, 2004Date of Patent: May 16, 2006Assignee: Seiko Epson CorporationInventor: Yoshihiro Kobayashi
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Patent number: 7046097Abstract: An integrated oscillator that may be used as a time clock includes circuitry that oscillates about an RC time constant, which RC time constant is adjustable to provide a desired frequency of oscillation. More specifically, the oscillator includes a capacitor array that has a plurality of capacitors coupled in parallel wherein each capacitor may be selectively included into the RC time constant or selectively excluded there from. Rather than setting the capacitance values to a desired capacitance value, a system for adjusting the time constant includes circuitry for measuring an output frequency and for comparing that to a certified frequency source wherein the time constant is adjusted by adding or removing capacitors from the capacitor array until the frequency of the internal clock matches an expected frequency.Type: GrantFiled: March 1, 2005Date of Patent: May 16, 2006Assignee: Broadcom CorporationInventors: Mike Kappes, Terje Gloerstad
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Patent number: 6995625Abstract: An oscillator that provides a quadrature output and has a cross-coupled configuration is disclosed. The oscillator generates an output signal having a frequency. Two phase shift circuits, or stages, are activated by a control signal to provide phase shifts within the oscillator. Each phase shift circuit includes poles to provide the phase shift. A pole includes a varactor to tune, adjust or vary the phase shift accordingly.Type: GrantFiled: March 31, 2004Date of Patent: February 7, 2006Assignee: Broadcom CorporationInventor: Hung-Ming Chien
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Patent number: 6987423Abstract: A voltage controlled oscillator (VCO) for use in a personal area network synthesizer includes a delay cell (100), a first current amplifier (201, 203) for amplifying an input current, a resister capacitor (RC) tuning network (207, 209, 211) for varying the amount of amplification and delay of an output of the first current amplifier. A second current amplifier (213, 215) is then used for amplifying an output current from the RC tuning network. The invention includes a unique composite voltage variable capacitor (CVVC) (300) for precisely tuning the amount of delay presented by the delay cell. The unique topology of the delay cell (100) allows it to be readily used in voltage controlled oscillators (VCOs) operable at frequencies above 1 GHz.Type: GrantFiled: August 19, 2003Date of Patent: January 17, 2006Assignee: Freescale Semiconductor, Inc.Inventors: Daniel E. Brueske, David B. Harnishfeger, Stephen T. Machan
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Patent number: 6980061Abstract: The problem of interference and coupling between circuits that arises in reducing the size of a voltage-controlled oscillator by using low temperature co-fired ceramics (LTCC) substrate technology is alleviated. A voltage-controlled oscillator includes an amplifier a surface acoustic wave device 15 that forms a feedback circuit for the amplifier; a frequency adjuster that is provided the feedback circuit and has a filter configuration; a phase shifter 13 including a hybrid coupler having an additional controller that receives a control voltage from an external source and changes a phase in an oscillation loop; an equal power distributor 12 that equally distributes output power in the oscillation loop and outputs the power to the outside of the oscillation loop; and a delay line 16 concentratedly provided a place where coupling or interference does not occur the oscillation loop for correcting a phase condition in the oscillation loop.Type: GrantFiled: May 3, 2004Date of Patent: December 27, 2005Assignees: Seiko Epson Corporation, NGK Insulators, Ltd.Inventors: Yutaka Takada, Kenji Suzuki, Tatsuya Tsuruoka
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Patent number: 6963252Abstract: Controllable oscillator circuit comprising a regenerative loop which incorporates a cascade circuit of first and second sections each having a controllable gain and a phase shift which is 90° at the oscillation frequency, the first and second sections comprising first and second transconductance amplifiers, respectively, outputs of which are coupled to third and fourth transconductance amplifiers, which are positively fed back from the output to the input, and via first and second capacitors to inputs of the second and first gain controlled amplifiers, said first and second capacitors being coupled in parallel to first and second load resistors, respectively, a tuning control current being supplied to control inputs of the first and second transconductance amplifiers, the output of at least one of the first and second transconductance amplifiers being coupled to an amplitude detection arrangement providing a gain control current for an automatic gain control to control inputs of the third and fourth transcondType: GrantFiled: April 12, 2002Date of Patent: November 8, 2005Assignee: Semiconductors Ideas to Market B.V.Inventor: Wolfdietrich Georg Kasperkovitz
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Patent number: 6909335Abstract: An oscillator for a DC-DC converter, which is able to obtain constant frequency by using trans-conductance value as a clock of the DC-DC converter to make an output insensitive for process changes, comprises: a trans-conductance unit calculating trans-conductance value according to input voltage, deciding and outputting current according to the input voltage; a capacitor charged by the current outputted from the trans-conductance unit; and an amp-type Schmitt trigger comparing the voltage charged in the capacitor to threshold voltage, and outputting the compared value.Type: GrantFiled: March 4, 2003Date of Patent: June 21, 2005Assignee: LG Electronics Inc.Inventor: Jong-Hyug Bae
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Patent number: 6900701Abstract: Oscillator circuitry on an integrated circuit automatically detects the presence or absence of an external resistor which is used to bias and set the frequency of an internal resistor-capacitor (RC) oscillator. If the resistor is present, the RC oscillator begins to oscillate to generate an oscillator clock. The presence of the oscillator clock is detected, and the RC oscillator continues to generate the oscillator clock. If the resistor is not present, the RC oscillator does not begin to oscillate. The absence of the oscillator clock is detected, and the oscillator circuitry automatically re-configures itself to generate the oscillator clock from an internal crystal oscillator circuit employing an external crystal.Type: GrantFiled: March 31, 2003Date of Patent: May 31, 2005Assignee: Texas Instruments IncorporatedInventor: Brian P. Lum Shue Chan
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Patent number: 6894574Abstract: A CR oscillation circuit includes an oscillation unit having first through third invertion circuits connected in series between a first node and a second node, a capacitance element provided between the first node and an output terminal of the second inverting circuit, and a switch part for electrically connecting the first and second nodes according to a level of a control voltage; a constant current unit for allowing a constant current to flow according to a resistance value of an externally-provided resistive element to thereby supply a constant voltage; and a level conversion unit for converting a level of the constant voltage to thereby produce the control voltage.Type: GrantFiled: March 21, 2003Date of Patent: May 17, 2005Assignee: Oki Electric Industry Co., Ltd.Inventor: Shigeru Nagatomo
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Patent number: 6882235Abstract: An integrated oscillator that may be used as a time clock includes circuitry that oscillates about an RC time constant, which RC time constant is adjustable to provide a desired frequency of oscillation. More specifically, the oscillator includes a capacitor array that has a plurality of capacitors coupled in parallel wherein each capacitor may be selectively included into the RC time constant or selectively excluded there from. Rather than setting the capacitance values to a desired capacitance value, a system for adjusting the time constant includes circuitry for measuring an output frequency and for comparing that to a certified frequency source wherein the time constant is adjusted by adding or removing capacitors from the capacitor array until the frequency of the internal clock matches an expected frequency.Type: GrantFiled: October 28, 2003Date of Patent: April 19, 2005Assignee: Broadcom CorporationInventors: Mike Kappes, Terje Gloerstad
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Patent number: 6882234Abstract: An oscillator (100, 200) and a method of adjusting the frequency of oscillation of the oscillator (100, 200) are disclosed for generating a signal with an adjustable frequency in a frequency range from 1 GHZ to 200 GHz. The oscillator (100, 200) includes a loop circuit. The loop circuit has an amplifier (101), a delay element or filter (103), a phase shifter (102), a device for adjusting the phase shifter (102), and a coupler (104) to provide an output signal. The adjusting device is coupled to the phase shifter (102).Type: GrantFiled: August 14, 2001Date of Patent: April 19, 2005Assignees: Commonwealth Scientific and Industrial Research Organisation, Mimix Broadband, Inc.Inventors: Alan C. Young, James Harvey, Terrence M. P. Percival
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Patent number: 6825735Abstract: A power supply voltage-independent and temperature-independent RC oscillator using a controllable Schmitt trigger comprises a transition voltage generator circuit, a Schmitt trigger circuit, an RC delay circuit, and a quantizer. The transition voltage generator circuit generates a high transition voltage and a low transition voltage. The high and low transition voltages are proportional to a power supply voltage. The Schmitt trigger circuit generates an output voltage having a first level when an input voltage becomes greater than the high transition voltage and having a second level when the input voltage becomes less than the low transition voltage. The RC delay circuit comprises a resistor and a capacitor and generates the input voltage in response to the output voltage. The quantizer quantizes the input voltage to output a square-wave oscillation signal. Accordingly, an oscillation signal having a stable oscillation frequency unaffected by the external conditions can be obtained.Type: GrantFiled: March 25, 2003Date of Patent: November 30, 2004Assignee: Samsung Electronics Co., Ltd.Inventor: Kyu-young Chung
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Publication number: 20040233008Abstract: An oscillator circuit is a closed loop including an amplifying circuit and a feedback circuit. The amplifying circuit includes a pair of amplifiers, which also function as impedance buffers, and a first phase-shift circuit. The feedback circuit includes a second phase-shift circuit and a piezoelectric vibrator. The second phase-shift circuit is capable of adjusting the phase and gain of the feedback circuit. The first phase-shift circuit of the amplifying circuit is arranged between the pair of amplifiers and is separated, in terms of impedance, from the second phase-shift circuit. The first phase-shift circuit is capable of adjusting the phase of the entire closed loop.Type: ApplicationFiled: March 15, 2004Publication date: November 25, 2004Inventor: Yoshihiro Kobayashi