With Parasitic Oscillation Control Or Prevention Means Patents (Class 331/105)
  • Patent number: 9692355
    Abstract: An oscillator for high-frequency signal generation is disclosed. Provided according to the present invention is an oscillator for high-frequency signal generation comprising: a first transistor comprising a first collector for receiving a power supply voltage from a load, a first base connected to a ground, and a first emitter connected to the first base; and a second transistor comprising a second collector for receiving a power supply voltage from the load, a second base connected to a ground, and a second emitter connected to the second base, the oscillator having a common-base cross-coupled structure in which the first collector and the second emitter are cross-coupled and the second collector and the first emitter are cross-coupled.
    Type: Grant
    Filed: December 10, 2014
    Date of Patent: June 27, 2017
    Assignee: KOREA UNIVERSITY RESEARCH AND BUSINESS FOUNDATION
    Inventors: Jae Sung Rieh, Jong Won Yun, Nam Hyung Kim
  • Patent number: 9531323
    Abstract: A circuit includes: first and second output terminals; a reference resonator coupled between the first and second output terminals; a cross-coupled oscillation unit coupled to the first and second output terminals; a first MOSFET diode coupled to the cross-coupled oscillation unit, the first MOSFET diode including a first transistor, a first resistor coupled between gate and drain terminals of the first transistor, and a first capacitor; a second MOSFET diode coupled to the cross-coupled oscillation unit, the second MOSFET diode including a second transistor, a second resistor coupled between gate and drain terminals of the second transistor, and a second capacitor cross coupled between the drain terminal of the second transistor and the gate terminal of the first transistor, wherein the first capacitor is cross coupled between the drain terminal of the first transistor and the gate terminal of the second transistor.
    Type: Grant
    Filed: June 24, 2015
    Date of Patent: December 27, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Alireza Khalili, Yashar Rajavi, Mazhareddin Taghivand
  • Patent number: 9490746
    Abstract: A voltage-controlled oscillator and a method for tuning oscillations. The oscillator comprises a resonator input connected to an oscillator core and a frequency tuning network. The oscillator core and resonator input are isolated from the frequency tuning network by inductors. The method comprises generating oscillations, tuning the frequency of the oscillations by varying a capacitance, and isolating one or more of noise sources or parasitic capacitances from the tuning network.
    Type: Grant
    Filed: August 27, 2015
    Date of Patent: November 8, 2016
    Assignee: Maxlinear Asia Singapore PTE LTD
    Inventors: Srinivasa Rao Madala, Bharath Kumar Singareddy, Hormoz Djahanshahi, Stanley Ho
  • Patent number: 9444401
    Abstract: Methods and devices for the generation of high frequency clock signals. In a transmission line a signal is reflected back and forward. The electric length of the transmission line determines the frequency of the oscillation. A start signal at the switching device initiates a signals traveling down the transmission line. At the other end of the transmission line the signals is reflected back. At the tapping point along the transmission line, part of the energy of the signal in the transmission line is coupled out to form the feedback signal. The feedback signal activates the switching device. The switching device injects energy into the transmission line and sustains the oscillation on the transmission line. The position of the tapping point on transmission line determines the shape of the feedback signals and can hence be used as a design parameter optimize the performance of the system.
    Type: Grant
    Filed: November 25, 2014
    Date of Patent: September 13, 2016
    Assignee: S9ESTRE, LLC
    Inventor: Bernd Schafferer
  • Patent number: 9019025
    Abstract: An oscillator configured to oscillate an electromagnetic wave, including: a negative resistance device; a microstrip resonator configured to determine an oscillation frequency of an electromagnetic wave excited by the negative resistance device; a resistance device and a capacitance device, which form a low-impedance circuit configured to suppress parasitic oscillation; and a strip conductor configured to connect the capacitance device of the low-impedance circuit and the microstrip resonator to each other, in which an inductance L of the strip conductor and a capacitance C of the microstrip resonator produce a resonance frequency of ½??LC, and ¼ of an equivalent wavelength of the resonance frequency is larger than a distance between the negative resistance device and the resistance device of the low-impedance circuit via the strip conductor, is provided.
    Type: Grant
    Filed: May 14, 2013
    Date of Patent: April 28, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventor: Ryota Sekiguchi
  • Publication number: 20150084708
    Abstract: A voltage controlled oscillator (VCO) with low phase noise and a sharp output spectrum is desirable. The present disclosure provides embodiments of LC tank VCOs that generate output signals with less phase noise compared with conventional LC tank VCOs, while at the same time limiting additional cost, size, and/or power. The embodiments of the present disclosure can be used, for example, in wired or wireless communication systems that require low-phase noise oscillator signals for performing up-conversion and/or down-conversion.
    Type: Application
    Filed: December 5, 2014
    Publication date: March 26, 2015
    Applicant: Broadcom Corporation
    Inventors: Farid SHIRINFAR, Tirdad Sowlati, Maryam Rofougaran, Ahmadreza Rofougaran
  • Patent number: 8878615
    Abstract: The present application discloses a voltage-controlled oscillator device and a method of correcting the voltage-controlled oscillator. The voltage-controlled oscillator device comprises predistortion module, configured to predistort an input voltage to obtain a predistorted voltage; and a voltage-controlled oscillator, configured to generate an output signal with a corresponding oscillation frequency according to the predistorted voltage, wherein the predistortion module corrects a non-linear characteristic of the voltage-controlled oscillator, so that there is a linear relationship between the input voltage and the oscillation frequency of the output signal. The voltage-controlled oscillator device may be applied to a phase-locked circuit in a communication system.
    Type: Grant
    Filed: October 9, 2011
    Date of Patent: November 4, 2014
    Assignee: Institute of Microelectronics, Chinese Academy of Sciences
    Inventors: Yuping Wu, Lan Chen
  • Publication number: 20140300423
    Abstract: Disclosed herein are a clock generating circuit having a parasitic oscillation suppressing unit and a method of suppressing parasitic oscillation using the same. An output VDD of a parasitic component eliminating circuit is maintained in a high or low state according to the condition in which the output VDD falls from the high state to the low state and the condition in which the output VDD rises from the low state to the high state based on a threshold voltage VSPH when an input signal of the parasitic component eliminating circuit is changed from 0 to 1 and a threshold voltage VSPL when the input signal of the parasitic component eliminating circuit is changed from 1 to 0. Undesired parasitic oscillation is eliminated (suppressed) by the parasitic component eliminating circuit provided between a oscillator and a buffer.
    Type: Application
    Filed: October 8, 2013
    Publication date: October 9, 2014
    Applicant: Samsung Electro-mechanics Co., Ltd.
    Inventor: Yo Sub MOON
  • Publication number: 20130328635
    Abstract: An oscillator configured to oscillate an electromagnetic wave, including: a negative resistance device; a microstrip resonator configured to determine an oscillation frequency of an electromagnetic wave excited by the negative resistance device; a resistance device and a capacitance device, which form a low-impedance circuit configured to suppress parasitic oscillation; and a strip conductor configured to connect the capacitance device of the low-impedance circuit and the microstrip resonator to each other, in which an inductance L of the strip conductor and a capacitance C of the microstrip resonator produce a resonance frequency of ½??LC, and ¼ of an equivalent wavelength of the resonance frequency is larger than a distance between the negative resistance device and the resistance device of the low-impedance circuit via the strip conductor, is provided.
    Type: Application
    Filed: May 14, 2013
    Publication date: December 12, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Ryota Sekiguchi
  • Patent number: 8606376
    Abstract: A method of actuating a system comprising a movable component and an actuator configured to move the movable component comprises providing a control signal representative of a desired motion of the movable component. The control signal is supplied to one or more resonators. Each of the one or more resonators has a mode of oscillation representative of at least one elastic mode of oscillation of the system. The control signal is modified by subtracting from the control signal a signal representative of a response of the one or more resonators to the control signal. The actuator is operated in accordance with the modified control signal. Thus, undesirable elastic oscillations of the system which might occur if the system were operated with the original control system can be reduced.
    Type: Grant
    Filed: October 7, 2009
    Date of Patent: December 10, 2013
    Assignees: Mitutoyo Corporation, Bundesrepublik Deutschland, Endvertreten Durch den Präsidenten der Physikalisch-Technischen Bundesanstalt
    Inventors: Hartmut Illers, Kazuhiko Hidaka, Akinori Saito, Hans-Ulrich Danzebrink
  • Patent number: 8085087
    Abstract: A switched capacitor circuit includes a positive side capacitor coupled to a first positive side node; a first positive side switch element for selectively coupling the first positive side node to a second node according to a first control signal; and a precharge circuit coupled to the first positive side node for precharging the first positive side node to a precharge voltage for a predetermined time when the first positive side switch element is switched off according to the first control signal, and then for charging the first positive side node to a charge voltage until the first positive side switch element is switched on according to the first control signal. By rapidly precharging the first positive side node, the clock feedthrough effect is eliminated and the locking period of the VCO is shortened. Afterwards by charging the first positive side node, the phase noise of the VCO is minimized.
    Type: Grant
    Filed: October 9, 2009
    Date of Patent: December 27, 2011
    Assignee: Mediatek Inc.
    Inventor: En-Hsiang Yeh
  • Patent number: 7650119
    Abstract: A wireless communication device is disclosed wherein the voltage swing of a local oscillator (LO) signal is controlled to prevent overstressing semiconductor devices in a mixer to which the LO signal is supplied. A quadrature divider supplies the LO signal to the mixer. Digital calibration methodology controls the current that the quadrature divider draws from a power supply to set the voltage swing of the LO signal that the quadrature divider generates.
    Type: Grant
    Filed: January 27, 2006
    Date of Patent: January 19, 2010
    Assignee: Silicon Laboratories Inc.
    Inventors: Aslam A. Rafi, Donald A. Kerth
  • Patent number: 7626469
    Abstract: An electric circuit, for use in a phase lock loop circuit, the electric circuit comprising: a first circuit element, being a phase frequency detector or a charge pump; at least one LC resonant loop, the first circuit element forming part of the loop; and means arranged to reduce ringing in said at least one LC resonant loop.
    Type: Grant
    Filed: April 17, 2008
    Date of Patent: December 1, 2009
    Assignee: GloNav Ltd.
    Inventors: Ramesh Chokkalingam, Matteo Conta
  • Patent number: 7576619
    Abstract: An integrated circuit arrangement is disclosed. In one embodiment, the integrated circuit arrangement includes an output circuit having at least one first output connection which can provide a data signal, at least one first data output connection; and at least one first inductance connected between the at least one first output connection and the at least one data output connection.
    Type: Grant
    Filed: July 11, 2003
    Date of Patent: August 18, 2009
    Assignee: Infineon Technologies AG
    Inventors: Daniel Kehrer, Herbert Knapp
  • Patent number: 7576687
    Abstract: An RF front-end circuit includes a directional coupler, a mixer, and a reflection circuit. The directional coupler is adapted to receive an antenna signal and an oscillator signal. The mixer is coupled to the directional coupler to receive the antenna signal and is further adapted to receive a mixer signal and to generate an output signal related to the antenna signal and the mixer signal. The reflection circuit is coupled to the directional coupler to receive the oscillator signal and is adapted to reflect at least a portion of the oscillator signal to the mixer via the directional coupler to counteract a parasitic portion of the oscillator signal received at the mixer.
    Type: Grant
    Filed: July 17, 2007
    Date of Patent: August 18, 2009
    Assignee: Infineon Technologies AG
    Inventor: Johann Peter Forstner
  • Patent number: 7365610
    Abstract: The effect of supply voltage variations on an oscillator circuit output are compensated for to reduce supply pushing. The change in a value of a first capacitance in a first direction in response to the variation in the supply voltage is canceled using one or more diodes having a capacitance that changes in a second direction, opposite the first direction, in response to the variation in the supply voltage.
    Type: Grant
    Filed: March 21, 2005
    Date of Patent: April 29, 2008
    Assignee: Silicon Laboratories Inc.
    Inventor: Ligang Zhang
  • Patent number: 7307484
    Abstract: A semiconductor integrated circuit device includes a semiconductor substrate; at least one integrated circuit block formed in the semiconductor substrate; a first electrode pad which receives a first clock, the first electrode pad being disposed on the semiconductor substrate; a wiring line which electrically connects the integrated circuit block and the first electrode pad, the wiring line being disposed on the semiconductor substrate; and a second electrode pad which receives a second clock having the same frequency as and opposite polarity from the first clock, the second electrode pad being disposed in a position adjacent to the first electrode pad on the semiconductor substrate and isolated from the integrated circuit block.
    Type: Grant
    Filed: April 4, 2005
    Date of Patent: December 11, 2007
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Hiroaki Inoue
  • Patent number: 7253693
    Abstract: A variable capacitance circuit includes a first and a second capacitor. A switch having an associated first nonlinear capacitance, selectively couples the first and second capacitors. To compensate for the first nonlinear capacitance, a second nonlinear capacitance is coupled to the switch that has a capacitance value responsive to a change in voltage that moves in a direction of change opposite to a direction of change of the first nonlinear capacitance.
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: August 7, 2007
    Assignee: Silicon Laboratories Inc.
    Inventors: Ligang Zhang, Yunteng Huang
  • Patent number: 7209010
    Abstract: An oscillator includes a resonant circuit of at least one inductance device and at least one tunable capacitance. The tunable capacitance is implemented through diffusion capacitances of at least one current-carrying transistor. The tunable capacitance has a first differential amplifier having a first transistor and a second transistor and a second differential amplifier having a third transistor and a fourth transistor Electrical properties of the first transistor and second transistor are complementary to electrical properties of the third transistor and fourth transistor, and control connections of the first transistor and the third transistor are connected to one another. Control connections of the second transistor and the fourth transistor are connected to one another. Second current connections of the first transistor and the third transistor are connected to one another, and second current connections of the second transistor and the fourth transistor are connected to one another.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: April 24, 2007
    Assignee: Atmel Germany GmbH
    Inventor: Hans-Peter Waible
  • Patent number: 7173498
    Abstract: Disclosed are integrated circuits having multiple electromagnetically emissive devices, such as LC oscillators. The devices are formed on an integrated circuit substrate and are given different planar orientations from each other. Particular integrated circuit packages disclosed are “flip-chip” packages, in which solder bumps are provided on the integrated circuit substrate for flipping and mounting of the finished integrated circuit upon a printed circuit board or other substrate. The solder bumps provide conductive connections between the integrated circuit and the substrate. The orientations and positioning of the emissive devices are such that one or more of the solder bumps are interposed between neighboring emissive devices to act as an electromagnetic shield between them.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: February 6, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Sridhar Ramaswamy, Hassan O. Ali, Song Wu
  • Patent number: 7132896
    Abstract: A method, an apparatus, and a computer program are provided to minimize filter capacitor leakage in a Phased Locked Loop (PLL). In high frequency processors and devices, filter leakage currents can cause substantial problems by causing PLLs to drift out of phase lock. To combat the leakage currents, a dummy filter and other components are employed to provide additional charge or voltage to a low pass filter during lock. The provision of the charge or voltage exponentially decreases the rate of decay of voltage across the low pass filter caused by leakage currents.
    Type: Grant
    Filed: November 4, 2004
    Date of Patent: November 7, 2006
    Assignee: International Business Machines Corporation
    Inventors: David William Boerstler, Eskinder Hailu, Jieming Qi
  • Patent number: 7067842
    Abstract: The present invention includes a method and apparatus for measuring a parasitic inductance associated with a portion of an integrated circuit fabricated on a semiconductor substrate. A test chip for measuring the parasitic inductance is fabricated together with the integrated circuit on the semiconductor substrate. The test chip includes an LC oscillator circuit having at least one substructure that resembles the portion of the integrated circuit and at least one varactor having a capacitance adjustable by a control voltage. When the LC oscillator circuit is connected to the control voltage source and the control voltage is at a certain level, an oscillation is generated in the LC oscillator and the frequency of oscillation can be used to determine the parasitic inductance associated with the portion of the integrated circuit.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: June 27, 2006
    Assignee: Altera Corporation
    Inventors: Jayakannan Jayapalan, Liping Li, Yow-Juang Liu
  • Patent number: 6927640
    Abstract: A resonant oscillator circuit includes an active device and a resonator that causes the active device to oscillate at a resonant frequency of the resonator. The active device includes one or more transistors that are DC biased using one or more resistors. The bias resistors generate thermal noise that is proportional to the resistance value. An external inductor circuit is connected across the output terminals of the active device and in parallel with the resonator. The external inductor circuit shorts-out at least some of the thermal noise that is generated by the bias resistors, and thereby reduces the overall phase noise of the resonant oscillator.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: August 9, 2005
    Assignee: Broadcom Corporation
    Inventor: Ramon A. Gomez
  • Patent number: 6798304
    Abstract: A resonant oscillator circuit includes an active device and a resonator that causes the active device to oscillate at a resonant frequency of the resonator. The active device includes one or more transistors that are DC biased using one or more resistors. The bias resistors generate thermal noise that is proportional to the resistance value. An external inductor circuit is connected across the output terminals of the active device and in parallel with the resonator. The external inductor circuit shorts-out at least some of the thermal noise that is generated by the bias resistors, and thereby reduces the overall phase noise of the resonant oscillator.
    Type: Grant
    Filed: October 24, 2003
    Date of Patent: September 28, 2004
    Assignee: Broadcom Corporation
    Inventor: Ramon A. Gomez
  • Patent number: 6639478
    Abstract: A resonant oscillator circuit includes an active device and a resonator that causes the active device to oscillate at a resonant frequency of the resonator. The active device includes one or more transistors that are DC biased using one or more resistors. The bias resistors generate thermal noise that is proportional to the resistance value. An external inductor circuit is connected across the output terminals of the active device and in parallel with the resonator. The external inductor circuit short-out at least some of the thermal noise that is generated by the bias resistors, and thereby reduces the overall phase noise of the resonant oscillator.
    Type: Grant
    Filed: July 22, 2002
    Date of Patent: October 28, 2003
    Assignee: Broadcom Corporation
    Inventor: Ramon A. Gomez
  • Patent number: 6639476
    Abstract: A digitally tuned oscillator synthesizer having a correlator circuit and selectable voltage controlled oscillators is disclosed. The correlator circuit develops an accurate output which provides frequency stability for the synthesizer, whereas the voltage oscillators each operate over less than an octave of a desired RF frequency output, but cooperatively operate to produce RF outputs over a wide range of frequencies.
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: October 28, 2003
    Inventor: William B. Sullivan
  • Patent number: 6611179
    Abstract: A voltage-controlled oscillator has a structure that is very compact and prevents characteristic deterioration. The voltage-controlled oscillator includes a first resonant circuit resonating in a first frequency band, a second resonant circuit resonating in a second frequency band that is higher than the first frequency band, an oscillation circuit oscillating at a resonance frequency of each of the first and second resonant circuits, an amplifying circuit amplifying an oscillation signal transmitted from the oscillation circuit, a control terminal applying a control voltage to each of the first and second resonant circuits, a power-source terminal commonly connected to the oscillation circuit and the amplifying circuit, and an output terminal outputting a high frequency signal.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: August 26, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Yoshiyuki Mashimo
  • Patent number: 6525617
    Abstract: A two-stage ring oscillator system that provides a phase shift of 90° in each of the two stages. Each stage includes an LC-based stage including a voltage controlled oscillator (VCO) and an in-line signal buffer that provides an additional controllable phase shift in the forward path and reduces loading capacitance of each LC-based stage by an estimated 10-50 percent. In-phase and quadrature output signals are provided by the system.
    Type: Grant
    Filed: August 9, 2001
    Date of Patent: February 25, 2003
    Assignee: Lattice Semiconductor Corporation
    Inventors: Edwin Chan, Ming Qu, Ji Zhao
  • Patent number: 6507248
    Abstract: Disclosed is an integrated voltage-controlled crystal oscillator intended to present the conditions for circuit constants in an oscillator circuit that can improve the oscillator's frequency tuning range with respect to the variable capacitance range of a variable-capacitance element. The voltage-controlled crystal oscillator comprises a crystal, an amplifier, and a load capacitor, wherein the load capacitor includes a voltage-controlled variable-capacitance element integrated on a semiconductor substrate and a DC cut capacitor element connected in series with the voltage-controlled variable-capacitance element, and the DC cut capacitor element has a capacitance value (Ccut) whose ratio to a maximum capacitance value (Cvmax) of the voltage-controlled variable-capacitance element (Ccut/Cvmax) is more than 0.5 and not more than 10.
    Type: Grant
    Filed: May 25, 2001
    Date of Patent: January 14, 2003
    Assignee: Citizen Watch Co., Ltd.
    Inventor: Rikoku Nakamura
  • Patent number: 6437652
    Abstract: A resonant oscillator circuit includes an active device and a resonator that causes the active device to oscillate at a resonant frequency of the resonator. The active device includes one or more transistors that are DC biased using one or more resistors. The bias resistors generate thermal noise that is proportional to the resistance value. An external inductor circuit is connected across the output terminals of the active device and in parallel with the resonator. The external inductor circuit shorts-out at least some of the thermal noise that is generated by the bias resistors, and thereby reduces the overall phase noise of the resonant oscillator.
    Type: Grant
    Filed: February 15, 2001
    Date of Patent: August 20, 2002
    Assignee: Broadcom Corporation
    Inventor: Ramon A. Gomez
  • Patent number: 6437651
    Abstract: An electric potential of an epitaxial layer 2A provided under a bonding pad 5 to which a resonance circuit for a VCO is to be connected is fixed to a predetermined (Vcc) electric potential through a resistor 6 in a conventional floating state. Consequently, a speed of a change in the electric potential of the epitaxial layer 2A is increased and a value of a parasitic capacity is stabilized quickly. Consequently, a drift can be improved when a power supply is turned ON.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: August 20, 2002
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Hirokazu Chigira, Masao Okumura, Tatsuro Koyanagi, Naoshi Mashimo, Tomoyuki Saito, Mitsuo Osawa, Nobukazu Hayakawa, Kouki Kubo
  • Patent number: 6215367
    Abstract: The reduction of interfering influences in an LC resonant circuit with an integrated circuit is effected by including the interfering elements of the housing in the resonant circuit. This precludes the occurrence of parasitic radio-frequency oscillation modes. It also ensures good radio-frequency properties and a wide frequency tuning range.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: April 10, 2001
    Assignee: Deutsche Thomson-Brandt GmbH
    Inventors: Phillippe Blaud, Martin Rieger, Heinrich Schemmann
  • Patent number: 6140882
    Abstract: The present invention, generally speaking, provides a PLL that enables smooth switching of loop bandwidth without changing the loop filter. In accordance with one aspect of the invention, the loop bandwidth of a phase lock loop including an output frequency divider and a reference frequency divider is changed by changing a divisor of the output frequency divider by a factor and changing a divisor of the reference frequency divider by substantially the same factor. If the factor is greater than one, the loop bandwidth is decreased. If the factor is less than one, then the loop bandwidth is increased. In accordance with another aspect of the invention, a phase lock loop includes an oscillator having a control input, a phase comparator, a loop filter, and a feedback path including an output frequency divider. A reference frequency divider is also provided.
    Type: Grant
    Filed: November 23, 1998
    Date of Patent: October 31, 2000
    Assignee: Tropian, Inc.
    Inventor: Brian Sander
  • Patent number: 6124766
    Abstract: A local oscillation circuit in a frequency converter circuit includes a resonant circuit, and a differential amplifier circuit connected to the resonant circuit. The differential amplifier circuit includes two transistors constituting a differential stage. One end of the resonant circuit is connected to the base of one transistor via a capacitive element, and to the collector of the other transistor via a capacitive element. The other end of the resonant circuit is connected to only the base of the other transistor via a capacitive element. Accordingly, an unbalanced oscillate operation is performed in the local oscillation circuit, leading to reduction of the phase noise caused by decrease in an oscillation output due to the trap phenomenon, and an improvement in reception quality.
    Type: Grant
    Filed: November 25, 1998
    Date of Patent: September 26, 2000
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Syuuji Matsuura
  • Patent number: 6107892
    Abstract: Phase noise in an RF oscillator is significantly reduced by loosely couping another quieter RF oscillator having noise patterns uncorrelated to the first RF oscillator so that it frequency locks with the first RF oscillator. The coupling is increased until a significant reduction in phase noise occurs at high coupling levels where the first RF oscillator displays phase noise similar to the the second RF oscillator.
    Type: Grant
    Filed: April 14, 1999
    Date of Patent: August 22, 2000
    Assignee: AT&T Corp.
    Inventor: Robert Raymond Miller, II
  • Patent number: 6091309
    Abstract: An oscillator comprises an active device with a phase shift of less than 180 degrees. A first delay line has first and second ends. The first end of the first delay line is coupled to an active port of the active device. A ring mode trap filter is coupled to the second end of the first delay line. A second delay line has first and second ends. The first end of the second delay line is coupled to the ring mode trap filter. The second end of the second delay line is coupled to a resonance means. The total delay of the first and second delay lines allows the resonance means to oscillate at its natural frequency in spite of the less-than-180-degree phase shift of the active device.
    Type: Grant
    Filed: January 26, 1998
    Date of Patent: July 18, 2000
    Inventors: Joseph P. Burke, Peter D. Heidmann
  • Patent number: 6046647
    Abstract: A Voltage Controlled Oscillator (VCO) mitigates the effects of package parasitics by providing positive feedback connections, to sustain a desired oscillation, external to the IC package, thereby mitigating the effect of the bond wires and internal parasitics to allow the oscillation to be controlled by the desired external components. The VCO includes an electronic circuit with gain that is at least part of an integrated circuit (IC) and a package for the IC. A passive resonant circuit may be provided external to the IC package. The positive feedback of the electronic circuit is provided through at least one additional lead of the package, such that the connection is external to the package.
    Type: Grant
    Filed: December 8, 1998
    Date of Patent: April 4, 2000
    Assignee: Lucent Technologies Inc.
    Inventor: Dale Harvey Nelson
  • Patent number: 5959503
    Abstract: A method (100) for tuning a voltage controlled oscillator by changing electrical circuit parasitics includes a first step (102) of providing a voltage controlled oscillator circuit on a circuit board and a plurality of different metal lids each having different numbers, sizes and locations of holes. Each different lid presents a different electrical circuit parasitic to the voltage controlled oscillator. In a second step (104), the voltage controlled oscillator frequency is measured, and the frequency shift needed to achieve a desired operating frequency is calculated in a third step (106). In a fourth step (108), a lid is chosen that will present the parasitics needed to provide the amount of frequency shift needed. As a last step (110), the chosen lid is attaching to the circuit board to obtain the desired nominal operating frequency from the voltage controlled oscillator.
    Type: Grant
    Filed: March 6, 1998
    Date of Patent: September 28, 1999
    Assignee: Motorola Inc.
    Inventors: Thomas A. Knecht, Glen O. Reeser
  • Patent number: 5841322
    Abstract: A phase detector responsive to a first signal having a carrier frequency and a second signal close to the carrier frequency, including a carrier suppression circuit which produces a carrier suppressed signal from the first and second signals, and a mixer responsive to the carrier suppressed signal and the carrier frequency to produce an output signal corresponding to the phase difference between the first and second signals.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: November 24, 1998
    Inventors: Eugene Nikolay Ivanov, Michael Edmund Tobar, Richard Alec Woode
  • Patent number: 5781074
    Abstract: A low noise clock oscillator in modular form to plug into a standard 14 or 8 pin DIP clock oscillator socket on the motherboard of a host device to retrofit the host device without redesign of the host device motherboard so that the host device can reduce its EMC emissions sufficiently to pass EMC emission tests. The oscillator is characterized by use of a spread spectrum clock generator, EMC filters between the clock generator and the Vcc, ground and clock bus coupling points to the motherboard and a single point ground connection to the motherboard. This oscillator module allows an easy retrofit to a host device that has already been designed to substantially lower EMC emissions that can be traced to the clock by as much as 20 dB without expensive, time consuming redesign efforts to add shielding, more grounds and possibly reroute the motherboard traces.
    Type: Grant
    Filed: August 9, 1996
    Date of Patent: July 14, 1998
    Inventors: Chuong Dinh Nguyen, James John Levante
  • Patent number: 5712598
    Abstract: A driving circuit and a Self-oscillating circuit incorporating a piezoelectric oscillator having one terminal connected to ground. In the driving circuit, an alternating driving power is supplied to a first terminal of the piezoelectric oscillator, and the second terminal of the piezoelectric oscillator is connected to ground. The damping capacitance of the piezoelectric oscillator is effectively canceled by connecting the first terminal to an input of an amplifier, and forming a feedback loop by connecting an output of the amplifier to the input through a electrostatic capacitance whose value is 1/N times the damping capacitance of the piezoelectric oscillator, where the amplifier has a gain of (N+1).
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: January 27, 1998
    Inventor: Yoshiro Tomikawa
  • Patent number: 5677650
    Abstract: A ring oscillator comprising an odd number of inverters connected in a ring, and apparatus for driving the ring oscillator so that it oscillates at a frequency slightly less than its maximum oscillating frequency such that harmonics of the oscillating frequency are suppressed.
    Type: Grant
    Filed: December 19, 1995
    Date of Patent: October 14, 1997
    Assignee: PMC-Sierra, Inc.
    Inventors: Tadeus Kwasniewski, Maamoun Abou-Seido, Stephan Iliasevitch
  • Patent number: 5675295
    Abstract: A millimeter or microwave oscillator device for a receiver or a transmitter is described. The oscillator device including a high frequency oscillating circuit including an active device 41; said active device 41 having a first and a second contact 56, 52, a signal line 49 of said oscillator device 41 being connected to said first contact 56 for connection to a load circuit 43; a biasing circuit 47 for said active device; and a low frequency oscillation suppression circuit; wherein said low frequency oscillation suppression circuit includes a decoupling capacitor 45 and one electrode of said decoupling capacitor 45 is connected to said second contact 52. A manufacturing method for the oscillator device is also disclosed.
    Type: Grant
    Filed: May 8, 1996
    Date of Patent: October 7, 1997
    Assignee: IMEC vzw
    Inventors: Steven Brebels, Kristel Fobelets, Philip Pieters, Eric Beyne, Gustaaf Borghs
  • Patent number: 5568096
    Abstract: An apparatus and method are provided for increasing the effective Q-value of an oscillator so that the required Q-value can be reached with the use of a low Q-value oscillator. In this apparatus and method, the FM noise is measured at the output of the oscillator by an FM detector and the output of the FM detector is fed back to the control input of the oscillator. By using this negative FM feedback, frequency variations in the oscillator output are suppressed by applying a correction signal at the control input of the oscillator. The amount of suppression depends on the loop gain of the FM feedback loop and the amount of suppression is proportional to the loop gain so that the effective Q-value of the oscillator is proportional to the loop gain.
    Type: Grant
    Filed: April 19, 1995
    Date of Patent: October 22, 1996
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Jacobus Haartsen
  • Patent number: 5302921
    Abstract: A piezoelectric oscillator in which radiation of higher harmonic components is reduced. A piezoelectric vibrator and a semiconductor device are provided in an oscillation circuit for making the piezoelectric vibrator oscillate, as is a filter for cutting components in a predetermined frequency band or higher harmonic components of an oscillation signal outputted from the semiconductor device. The piezoelectric vibrator, the semiconductor device and the filter are packed in one package. Radiation of the higher harmonic components is reduced by placing the filter close to the oscillator, by providing a shielding or by operating portions of the oscillator output circuit with a reduced supply voltage.
    Type: Grant
    Filed: April 16, 1992
    Date of Patent: April 12, 1994
    Assignee: Seiko Epson Corporation
    Inventors: Mikio Shigemori, Toru Oida, Shigeru Hirasawa, Katsumi Yamamura
  • Patent number: 5185585
    Abstract: Crystal oscillator and method which in one embodiment have a crystal element connected in a positive feedback loop with a charge amplifier and an integrator, with the gain of the loop being maintained at a level of unity. Compensation is provided to offset the effects of shunt capacitance in the crystal element, and precise phase control is maintained around the loop. In other embodiments, a crystal element is connected in a series feedback loop with a buffer amplifier, and operation is provided by maintaining the oscillation signal at level at which distortion, clipping, and saturation do not occur. Compensation for shunt capacitance across the crystal element is provided by applying a compensation signal which is equal in amplitude but opposite in phase to the signal passing through the shunt capacitance to the input terminal of the buffer amplifier to cancel the effect of the shunt capacitance.
    Type: Grant
    Filed: September 10, 1991
    Date of Patent: February 9, 1993
    Assignee: New SD, Inc.
    Inventors: Gerald R. Newell, Michael W. Nootbaar, Pradeep Bhardwaj, Robert C. Willson
  • Patent number: 5053726
    Abstract: An oscillator includes a mechanical resonator, such as a crystal, and having an amplifier arranged for oscillating at a first frequency. A resonant circuit is coupled in series with the crystal. The resonant circuit is antiresonant at an undesired harmonic frequency of the crystal thus prohibiting oscillation of the oscillator at said undesired harmonic frequency. The present oscillator is a portion of a phase locked loop used in a television receiver for demodulating a composite stereophonic audio signal.
    Type: Grant
    Filed: April 10, 1990
    Date of Patent: October 1, 1991
    Assignee: Thomson Consumer Electronics, Inc.
    Inventors: Todd J. Christopher, Robert E. Morris, Jr.
  • Patent number: 5047734
    Abstract: A series-feedback crystal oscillator has a crystal element in series with a buffer amplifier. The oscillator maintains a linear oscillation signal by using an amplitude control circuit to hold the oscillation signal to a certain level at which distortion, clipping, or saturation does not occur. A control signal indicative of the amplitude of the oscillation signal linearly multiplies the oscillation signal to control the amplitude of the oscillation signal. Shunt capacitance across the crystal is compensated for by connecting a compensating capacitor to the same input terminal of the buffer amplifier as is connected the crystal. A compensating signal, which is equal in amplitude but opposite in phase to the signal passing through the shunt capacitance of the crystal is fed to the input terminal of the buffer amplifier to cancel the effect of the shunt capacitance. A noninverted tracer signal is injected in the feedback loop and passes through the shunt capacitance.
    Type: Grant
    Filed: May 30, 1990
    Date of Patent: September 10, 1991
    Assignee: New SD, Inc.
    Inventors: Gerald R. Newell, Michael W. Nootbaar, Pradeep Bhardwaj
  • Patent number: 4864256
    Abstract: An oscillator for producing an oscillating signal with reduced harmonics includes an oscillator stage coupled to an output stage having a relatively fast switching speed yet producing an oscillating signal having relatively slow rise and fall times so that the harmonics output by the oscillator are reduced. In one embodiment, the oscillator includes an output stage having low power Schottky circuitry, and in a second embodiment, the output stage includes a capacitor connected across the output stage of the oscillator to increase the rise and fall times of the oscillator.
    Type: Grant
    Filed: September 9, 1988
    Date of Patent: September 5, 1989
    Assignee: Spectrum Control, Inc.
    Inventor: Armin Barnert
  • Patent number: 4616193
    Abstract: A solid state oscillator circuit for operation at very high frequencies includes a field effect transistor having an input network connected between its gate and source electrodes and an output network connected between its drain and source electrodes, the input and output networks each including three discrete capacitors connected in a "pi" configuration, the input and output networks being connected in series with one another, and an inductor being connected in parallel with the series connected networks, the equivalent circuit impedance of the networks in series and the inductance determining the operating frequency of the oscillator circuit, and the relative ratio of impedance of the networks determining the amount of oscillator feedback.
    Type: Grant
    Filed: January 22, 1985
    Date of Patent: October 7, 1986
    Assignee: Northern Illinois Gas Company
    Inventor: Walter Meyer