Convertible (e.g., Oscillator To Amplifier, Etc.) Patents (Class 331/59)
  • Patent number: 9880119
    Abstract: An apparatus is provided for identifying a property value of a fluid which is to be measured, a method for operating such an apparatus, and a method for manufacturing such an apparatus. The apparatus encompasses: a measurement capacitor device bringable into contact with the fluid, the measurement capacitor device having a first electrode, a second electrode, a first dielectric layer, and a second dielectric layer; a first dielectric constant of the first dielectric layer being dependent, in a context of contact with the fluid, on the property of the fluid to be measured; a second dielectric constant of the second dielectric layer being substantially independent of the property of the fluid which is to be measured; a compensation capacitor device that has the second dielectric layer, a third electrode, and a fourth electrode; the compensation capacitor device connected in parallel, or connectable in parallel, with the measurement capacitor device.
    Type: Grant
    Filed: May 27, 2015
    Date of Patent: January 30, 2018
    Assignee: ROBERT BOSCH GMBH
    Inventors: Viktor Morosow, Dominik Geisler
  • Patent number: 9831841
    Abstract: Switchable base feed circuit for radio-frequency (RF) power amplifiers. In some embodiments, an RF power amplifier (PA) circuit can include a transistor having a base, a collector, and an emitter, with the transistor being configured to amplify an RF signal. The PA circuit can further include a bias circuit configured to provide a base bias signal to the base of the transistor. The PA circuit can further include a switchable base feed circuit implemented between the bias circuit and the base of the transistor. The switchable base feed circuit can be configured to provide a plurality of different resistance values for the base bias signal between the bias circuit and the base of the transistor. Such a PA circuit can be implemented in products such as a die, a module, and a wireless device.
    Type: Grant
    Filed: June 28, 2014
    Date of Patent: November 28, 2017
    Assignee: Skyworks Solutions, Inc.
    Inventors: Andy Cheng Pang Wu, Yu-Jui Lin, Florina Alexandra Lefter-Elarabi
  • Patent number: 9214895
    Abstract: One aspect of this disclosure is an apparatus including an oscillator that includes a secondary LC circuit to increase a tuning range of the oscillator and/or to reduce a phase noise of the oscillator. Another aspect of this disclosure is an apparatus that includes oscillator with a primary LC circuit and a secondary LC circuit. This oscillator can operate in a primary oscillation mode or a secondary oscillation mode, depending on whether oscillation is set by the primary LC circuit or the secondary LC circuit.
    Type: Grant
    Filed: March 10, 2014
    Date of Patent: December 15, 2015
    Assignee: Analog Devices, Inc.
    Inventor: Hyman Shanan
  • Patent number: 8952761
    Abstract: In accordance with some embodiments of the present disclosure, an oscillator circuit comprises, a first pad associated with a first terminal of an oscillator and a second pad associated with a second terminal of the oscillator. The oscillator is configured to generate an oscillating signal and communicate the oscillating signal from the second terminal to a clock distributor coupled to the second pad. The oscillator circuit further comprises an oscillator gain element comprising an output node coupled to the first pad and an input node coupled to the second pad. The oscillator circuit also comprises a digital-to-analog converter (DAC) coupled to the first pad. The oscillator circuit additionally comprises a switching circuit coupled to the gain element. The switching circuit is configured to enable the gain element when the oscillator comprises a resonator and disable the gain element when the oscillator comprises a voltage controlled oscillating module.
    Type: Grant
    Filed: June 6, 2013
    Date of Patent: February 10, 2015
    Assignee: Intel IP Corporation
    Inventors: Kristopher Kevin Kaufman, John Wayne Simmons
  • Patent number: 8878616
    Abstract: The described embodiments provide a configurable pulse generator circuit. More specifically, the described embodiments include a pulse generator circuit; an inverting difference oscillator (IDO) enabling circuit coupled to the pulse generator circuit; and a disable signal coupled to the IDO enabling circuit. When the disable signal is asserted, the IDO enabling circuit is disabled and the pulse generator circuit is configured as a pulse generator. In contrast, when the disable signal is deasserted, the IDO enabling circuit is enabled and the pulse generator circuit is configured as part of an IDO.
    Type: Grant
    Filed: January 31, 2011
    Date of Patent: November 4, 2014
    Assignee: Oracle International Corporation
    Inventors: Anand Dixit, Robert P. Masleid
  • Patent number: 8816789
    Abstract: A semiconductor device according to an exemplary aspect of the invention is capable of being selectively switched between an oscillation circuit and a signal input-output circuit, and includes first and second external connecting terminals that are connectable to an oscillation device; an inverting amplifier an input side of which is electrically connected to the first external connecting terminal through a coupling capacitor and an output side of which is electrically connected to the second external connecting terminal; a feedback resistor connected to the input side and the output side of the inverting amplifier; a bias stabilization circuit that stabilizes a bias applied to the coupling capacitor; a first signal input-output portion connected to the first external connecting terminal; and a second signal input-output portion connected to the second external connecting terminal.
    Type: Grant
    Filed: June 18, 2012
    Date of Patent: August 26, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Kazutoshi Sako, Tomokazu Matsuzaki, Kouji Yokosawa
  • Patent number: 8798198
    Abstract: A calibration system may be provided for calibrating wireless communications circuitry in an electronic device during manufacturing. The calibration system may include data acquisition equipment for receiving an amplitude-modulated calibration signal from the electronic device. The calibration system may include calibration computing equipment for extracting pre-distortion coefficients from the amplitude-modulated calibration signal. The calibration computing equipment may be configured to detect a bulk phase drift in the amplitude-modulated calibration signal. The calibration computing equipment may be configured to remove the bulk phase drift from the amplitude-modulated calibration signal. The wireless communications circuitry may include a power amplifier that distorts a signal generated by the wireless communications circuitry. The wireless communications circuitry may include a pre-distortion compensator for countering the distortion.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: August 5, 2014
    Assignee: Apple Inc.
    Inventor: Gary Lang Do
  • Patent number: 8710932
    Abstract: A signal processing device includes a signal processing chip and a conducting path. The signal processing chip includes: a first port capable of receiving a first oscillating signal; a second port capable of outputting a second oscillating signal derived from the first oscillating signal; and a third port. The conducting path is external to the signal processing chip and coupled to the second port and the third port, and the conducting path is capable of transmitting the second oscillating signal outputted from the second port to the third port.
    Type: Grant
    Filed: January 31, 2012
    Date of Patent: April 29, 2014
    Assignee: Mediatek Inc.
    Inventors: Hao-Jung Li, Tung-Yi Wang
  • Patent number: 8466752
    Abstract: In accordance with some embodiments of the present disclosure, an oscillator circuit comprises, a first pad associated with a first terminal of an oscillator and a second pad associated with a second terminal of the oscillator. The oscillator is configured to generate an oscillating signal and communicate the oscillating signal from the second terminal to a clock distributor coupled to the second pad. The oscillator circuit further comprises an oscillator gain element comprising an output node coupled to the first pad and an input node coupled to the second pad. The oscillator circuit also comprises a digital-to-analog converter (DAC) coupled to the first pad. The oscillator circuit additionally comprises a switching circuit coupled to the gain element. The switching circuit is configured to enable the gain element when the oscillator comprises a resonator and disable the gain element when the oscillator comprises a voltage controlled oscillating module.
    Type: Grant
    Filed: May 4, 2011
    Date of Patent: June 18, 2013
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Kristopher Kevin Kaufman, John Wayne Simmons
  • Patent number: 8447259
    Abstract: A mode-switching LNA generally includes an input unit, an output unit and a bias voltage generator. The input unit amplifies an input signal to generate an amplified signal. The output unit receives the amplified signal from the input unit and operates either in an oscillation mode or in an amplification mode in response to a control signal to generate an output signal having a center frequency equal to a target frequency. The control signal indicates whether the center frequency of the output signal is the same as the target frequency. The bias voltage generator provides an input bias voltage to the input unit in response to the control signal, where the input bias voltage includes a first bias voltage in the amplification mode and a second bias voltage in the oscillation mode.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: May 21, 2013
    Inventors: Jae-Hong Chang, Hyung-Ki Ahn, Hui-Jung Kim
  • Patent number: 8392743
    Abstract: A master clock generation unit for satellite navigation systems, comprises a plurality of frequency inputs for receiving a respective atomic clock signal, each having a first or a second reference frequency, and a number of frequency converters each having an input connected to one of the frequency inputs and an output. Each of the frequency converters receives an offset frequency (selected according to the first and second reference frequency at the assigned frequency input) from at least one frequency synthesizer, for providing the same intermediate frequency at each of the converter outputs. A switching matrix is connected to each of the converter outputs for selecting one of the intermediate frequencies as a primary clock provided at a first matrix output, and another of the intermediate frequencies as a secondary clock provided at a second matrix output.
    Type: Grant
    Filed: April 26, 2010
    Date of Patent: March 5, 2013
    Assignee: Astrium GmbH
    Inventor: Dirk Felbach
  • Patent number: 8217726
    Abstract: A semiconductor device according to an exemplary aspect of the invention is capable of being selectively switched between an oscillation circuit and a signal input-output circuit, and includes first and second external connecting terminals that are connectable to an oscillation device; an inverting amplifier an input side of which is electrically connected to the first external connecting terminal through a coupling capacitor and an output side of which is electrically connected to the second external connecting terminal; a feedback resistor connected to the input side and the output side of the inverting amplifier; a bias stabilization circuit that stabilizes a bias applied to the coupling capacitor; a first signal input-output portion connected to the first external connecting terminal; and a second signal input-output portion connected to the second external connecting terminal.
    Type: Grant
    Filed: September 27, 2010
    Date of Patent: July 10, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Kazutoshi Sako, Tomokazu Matsuzaki, Kouji Yokosawa
  • Patent number: 7724104
    Abstract: Constant and accurate signal gain systems based on controlling oscillator loop gain. A constant gain positive feedback network and an amplifier form an oscillator. Only when the oscillator loop gain is at least one does the oscillator produces an AC signal. Negative feedback of the oscillator's AC signal level is used to keep the loop gain close to or at the value of one by controlling the loop gain of the oscillator circuit. By maintaining the loop gain of the oscillator circuit substantially constant the signal gain is also maintained substantially constant.
    Type: Grant
    Filed: May 6, 2008
    Date of Patent: May 25, 2010
    Inventor: Fred A. Mirow
  • Patent number: 7626449
    Abstract: A method for tuning a filter is provided. The method includes: enabling a VCO circuit, wherein at least a portion of the VCO circuit is selected from the filter; generating an oscillation signal by the VCO circuit according to a driving signal; comparing the oscillation signal with a reference signal and generating a comparison result; and adjusting the driving signal according to the comparison result.
    Type: Grant
    Filed: June 16, 2008
    Date of Patent: December 1, 2009
    Assignee: Mediatek Inc.
    Inventors: Wei-Hsuan Tu, Tse-Hsiang Hsu
  • Patent number: 7512383
    Abstract: Systems, devices and methods are provided to switch between transmit and receive modes in wireless hearing aids. One aspect relates to an apparatus for use within a communication system that has an inductive coil connected to a tuning capacitor at a node. An amplifier is connected to the node through a DC blocking capacitor to receive an induced signal in the inductive coil in a receive mode. A driver energizes the inductive coil with a driven signal in a transmit mode. According to various embodiments, the apparatus transforms the inductive coil, the tuning capacitor and the DC blocking capacitor into an equivalent series resonant circuit to reduce an inductive load in the transmit mode, and transforms the inductive coil, the tuning capacitor and the DC blocking capacitor into an equivalent parallel resonant circuit to increase an inductive load in the receive mode.
    Type: Grant
    Filed: November 26, 2003
    Date of Patent: March 31, 2009
    Assignees: Starkey Laboratories, Inc., Oticon A/S
    Inventors: Mohamad Essabar, John David Terry
  • Patent number: 7474160
    Abstract: Calibrating a filter is disclosed. The filter is reconfigured as an oscillator during calibration. Switches and/or other implementations of reconfiguring a filter are used to reconfigure the negative feedback loop of the filter to a positive feedback loop. The oscillation parameters are then measured to adjust the components of the filter to achieve an oscillation that corresponds to a desired filter characteristic.
    Type: Grant
    Filed: May 23, 2006
    Date of Patent: January 6, 2009
    Assignee: QUALCOMM Incorporated
    Inventors: Ozan E. Erdogan, Jacques C. Rudell, Roger Brockenbrough
  • Publication number: 20080252365
    Abstract: A method for tuning a filter is provided. The method includes: enabling a VCO circuit, wherein at least a portion of the VCO circuit is selected from the filter; generating an oscillation signal by the VCO circuit according to a driving signal; comparing the oscillation signal with a reference signal and generating a comparison result; and adjusting the driving signal according to the comparison result.
    Type: Application
    Filed: June 16, 2008
    Publication date: October 16, 2008
    Inventors: Wei-Hsuan Tu, Tse-Hsiang Hsu
  • Patent number: 7403063
    Abstract: A tuning method and a tuning apparatus for tuning a filter are disclosed. The tuning method includes: configuring the filter as a VCO; utilizing the VCO to generate an oscillation signal according to a driving signal; comparing a frequency of the oscillation signal with a reference frequency to generate a comparison result; converting the comparison result into the driving signal in order to establish a feedback mechanism. Therefore, the inner components such as the gm and capacitance inside the VCO are completely tuned when the VCO generates an oscillation signal having a wanted frequency. Since the VCO is inside the filter and the components of the filter and the VCO are similar, the driving signal can be utilized to make the filter operate in a desired center frequency under a well-designed relationship between the frequency of the oscillation signal and the center frequency.
    Type: Grant
    Filed: October 30, 2006
    Date of Patent: July 22, 2008
    Assignee: MediaTek Inc.
    Inventors: Wei-Hsuan Tu, Tse-Hsiang Hsu
  • Patent number: 7164388
    Abstract: Inductor-capacitor (LC) RF resonator circuits are formed of a conductive loaded resin-based material. The conductive loaded resin-based material comprises micron conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers in a base resin host. The ratio of the weight of the conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers to the weight of the base resin host is between about 0.20 and 0.40. The micron conductive powders are formed from non-metals, such as carbon, graphite, that may also be metallic plated, or the like, or from metals such as stainless steel, nickel, copper, silver, that may also be metallic plated, or the like, or from a combination of non-metal, plated, or in combination with, metal powders. The micron conductor fibers preferably are of nickel plated carbon fiber, stainless steel fiber, copper fiber, silver fiber, or the like.
    Type: Grant
    Filed: April 19, 2004
    Date of Patent: January 16, 2007
    Assignee: Integral Technologies, Inc.
    Inventor: Thomas Aisenbrey
  • Publication number: 20040222863
    Abstract: Inductor-capacitor (LC) oscillator circuits are formed of a conductive loaded resin-based material. The conductive loaded resin-based material comprises micron conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers in a base resin host. The ratio of the weight of the conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers to the weight of the base resin host is between about 0.20 and 0.40. The micron conductive powders are formed from non-metals, such as carbon, graphite, that may also be metallic plated, or the like, or from metals such as stainless steel, nickel, copper, silver, that may also be metallic plated, or the like, or from a combination of non-metal, plated, or in combination with, metal powders. The micron conductor fibers preferably are of nickel plated carbon fiber, stainless steel fiber, copper fiber, silver fiber, or the like.
    Type: Application
    Filed: April 19, 2004
    Publication date: November 11, 2004
    Applicant: Integral Technologies, Inc.
    Inventor: Thomas Aisenbrey
  • Publication number: 20040196198
    Abstract: Inductor-capacitor (LC) RF resonator circuits are formed of a conductive loaded resin-based material. The conductive loaded resin-based material comprises micron conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers in a base resin host. The ratio of the weight of the conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers to the weight of the base resin host is between about 0.20 and 0.40. The micron conductive powders are formed from non-metals, such as carbon, graphite, that may also be metallic plated, or the like, or from metals such as stainless steel, nickel, copper, silver, that may also be metallic plated, or the like, or from a combination of non-metal, plated, or in combination with, metal powders. The micron conductor fibers preferably are of nickel plated carbon fiber, stainless steel fiber, copper fiber, silver fiber, or the like.
    Type: Application
    Filed: April 19, 2004
    Publication date: October 7, 2004
    Applicant: Integral Technologies, Inc.
    Inventor: Thomas Aisenbrey
  • Patent number: 6782485
    Abstract: A microcomputer is provided, which eliminates the need of input of a selection signal to select whether an external oscillator element is connected to generate an internal clock signal or an external clock signal is inputted to generate an internal clock signal. In this microcomputer, a delay circuit generates a delayed reset signal from an external reset signal to have a specific delay period. An external clock signal detection circuit detects an external clock signal at a second terminal, outputting a detection signal. An oscillation control signal generation circuit generates an oscillation control signal for an amplifier circuit, where the oscillation control signal is generated corresponding to a detection signal outputted from an external clock signal detection circuit. The oscillation control signal is used to activate the amplifier when the external clock signal does not exist at the second terminal and to inactivate the amplifier when the external clock signal exists at the second terminal.
    Type: Grant
    Filed: April 5, 2001
    Date of Patent: August 24, 2004
    Assignee: NEC Electronics Corporation
    Inventor: Hiroyuki Takai
  • Patent number: 6462626
    Abstract: A quadrature output oscillator device (22) includes a first voltage controlled oscillator (40) and a second voltage controlled oscillator (44). The second voltage controlled oscillator (44) generates a first output (C) and a second output (D) to drive a first amplifier (42). The second output (D) of the second voltage controlled oscillator (44) is a quadrature-phase signal component output (Q) of the quadrature output oscillator device (22). The first voltage controlled oscillator (40) generates a first output (A) and a second output (B) to drive a second amplifier (46). The second output (B) of the first voltage controlled oscillator (40) is an in-phase signal component output (I) of the quadrature output oscillator device (22). The first amplifier (42) generates feedback signals for the first output (A) and the second output (B) of the first voltage controlled oscillator (40).
    Type: Grant
    Filed: September 17, 1999
    Date of Patent: October 8, 2002
    Assignee: Texax Instruments Incorporated
    Inventor: Ranjit Gharpurey
  • Patent number: 5982243
    Abstract: An electronic oscillator of the Colpitts type with an amplifying element and a tank circuit. The tank circuit includes a parallel tuned resonant circuit, a series tuned resonant circuit and a switching circuit that selectively connects one of the resonant circuits to the tank circuit. The oscillator operates at a first frequency in the parallel tuned mode and a second frequency that is substantially twice the first frequency in the series tuned mode.
    Type: Grant
    Filed: May 4, 1999
    Date of Patent: November 9, 1999
    Assignee: Vari-L Company, Inc.
    Inventor: Matthew D. Pope
  • Patent number: 5900787
    Abstract: An oscillator circuit, having an inverter with input and output terminals interconnected through a feedback resistance, operates in two modes. In a first mode, the input and output terminals are coupled to an external crystal resonator. In a second mode, an external clock signal is supplied to the input terminal. In the second mode, the input terminal is disconnected from the output terminal, and in addition, the output-drive capacity of the inverter is reduced, or the output terminal of the inverter is held at a fixed potential.
    Type: Grant
    Filed: August 26, 1997
    Date of Patent: May 4, 1999
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Katsutoshi Yoshimura
  • Patent number: 5675294
    Abstract: A single pin integrated oscillator circuit includes an amplifier having a first input terminal to which an external crystal may be connected, and a second input terminal which receives a feedback path from an output terminal of the amplifier. An oscillator output signal having a relatively large voltage swing is provided from the first input terminal through a buffer. The oscillator operates over a wide range of voltages and process variations, and it can accept an input signal from an external crystal or can accept any clock signal having a swing of approximately 1 V.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: October 7, 1997
    Assignee: Sierra Semiconductor
    Inventors: Jyn-Bang Shyu, Jin Zhao
  • Patent number: 5416445
    Abstract: A clock pulse generator has a three-state inverter and a transfer gate forming in combination a feedback loop for oscillating an output clock signal in cooperation with a quartz resonator in an internal oscillation mode, and the three-state inverter enters into high-impedance state in an external oscillation mode so that an external clock signal is transferred to the output node of the three-state inverter without malfunction.
    Type: Grant
    Filed: August 1, 1994
    Date of Patent: May 16, 1995
    Assignee: NEC Corporation
    Inventor: Tetsuya Narahara
  • Patent number: 5369377
    Abstract: A self-configurable clock circuit which automatically detects at power up whether an off-chip crystal oscillator is connected to an integrated circuit including the self-configurable clock circuit, and following such detection generates a system clock signal and a power on reset signal to be used by other circuitry included in the integrated circuit. If the off-chip crystal oscillator is connected to the integrated circuit, then the self-configurable clock circuit provides the system clock signal from a first signal generated from the off-chip crystal oscillator. On the other hand, if the off-chip crystal oscillator is not connected to the integrated circuit, then the self-configurable clock circuit provides the system clock signal from a second signal generated from an on-chip RC oscillator circuit.
    Type: Grant
    Filed: October 13, 1993
    Date of Patent: November 29, 1994
    Assignee: Zilog, Inc.
    Inventor: Boubekeur Benhamida
  • Patent number: 5311150
    Abstract: An integrated oscillator includes an amplifier having first and second voltage inputs, and first and second current outputs, and a current mirror having an input coupled to the second current output of the amplifier and an output coupled to the first current output of the amplifier. The output of the current mirror and the first current output of the amplifier are coupled through a bonding pad to an external capacitor. A first comparator has a first input coupled to the first current output of the amplifier and a second input for receiving a first threshold voltage, and a second comparator has a first input coupled to the first current output of the amplifier and a second input for receiving a second threshold voltage. A flip-flop has a first input coupled to the output of the first comparator, a second input, and an output coupled to the second voltage input of the amplifier.
    Type: Grant
    Filed: September 18, 1992
    Date of Patent: May 10, 1994
    Assignee: Tektronix, Inc.
    Inventors: Michael R. Engbretson, Garry N. Link
  • Patent number: 5151613
    Abstract: An integrated circuit device having a CR oscillation circuit and a crystal oscillation circuit and capable of selecting either the CR oscillation circuit or the crystal oscillation circuit, includes a unit for receiving an electrical signal, and a unit for selecting either the CR oscillation circuit or the crystal oscillation circuit in accordance with a state of the electrical signal received by the receiving unit. The integrated circuit device also includes a unit for holding the receiving unit at a predetermined level of the electrical signal. The holding unit is adapted to hold the receiving unit at the predetermined level in accordance with a state of the receiving unit. The receiving unit is a selection terminal and the selecting unit is a selection circuit.
    Type: Grant
    Filed: August 7, 1991
    Date of Patent: September 29, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hiroki Satou, Kazuyuki Horinouchi
  • Patent number: 5093633
    Abstract: A circuit has a mask option for choosing between a crystal or an RC oscillator. The RC oscillator is completely fabricated on an integrated-circuit chip and includes a charging path, a discharging path, and a capacitor coupled at a node. The alternating charging and discharging of the node produces the oscillating output voltage signal at certain frequency. The oscillation frequency may be trimmed by coupling a single optional external resistor to either the charging or discharging paths, thereby reducing the output oscillation frequency.
    Type: Grant
    Filed: February 20, 1991
    Date of Patent: March 3, 1992
    Assignee: Zilog, Inc.
    Inventor: Boubekeur Benhamida
  • Patent number: 5088107
    Abstract: A calibration circuit for a linear channel of an optical modem includes circuitry interconnected to the linear channel for causing the linear channel to oscillate. Circuitry is interconnected to the output of the linear channel for monitoring the bandwidth of the linear channel during oscillation and for generating output pulses. The output pulses are counted and are utilized for generating an adjustment signal applied to the linear channel for adjusting the bandwidth of the linear channel.
    Type: Grant
    Filed: October 27, 1989
    Date of Patent: February 11, 1992
    Assignee: Crystal Semiconductor
    Inventors: Douglas S. Piasecki, Eric J. Swanson
  • Patent number: 4864639
    Abstract: An FM receiver is self tested by connecting a positive feedback network in circuit with a wideband, front end r.f. amplifier of the receiver, so that the amplifier is converted into an oscillator. R.f. and i.f. characteristics of the receiver are determined by comparing the amplitude of an i.f. signal with a predetermined reference value while the amplifier is converted to an oscillator. Noise characteristics of the receiver are determined by comparing the amplitude of an audio frequency signal of the receiver with a predetermined value while the amplifier is converted to an oscillator and the amplifier derives an unmodulated r.f. output. Baseband characteristics of the receiver are determined by varying a reactance in the positive feedback path to impose FM on r.f. oscillations derived by the amplifier and by comparing the amplitude of the output of the audio frequency amplifier with a predetermined value.
    Type: Grant
    Filed: September 28, 1987
    Date of Patent: September 5, 1989
    Assignee: Cincinnati Electronics Corporation
    Inventors: Mark A. Dapore, Daniel A. Titus
  • Patent number: 4613829
    Abstract: An oscillator circuit operable in different modes. The oscillator circuit, when operated as a crystal oscillator, is initially operated as a standard inverter oscillator requiring a low start-up voltage. Once the circuit oscillates, an hysteresis feedback network is inserted in the amplifying section of the oscillator providing a clock signal with sharper leading and falling edges. The circuit thus enables the start up of the oscillator at low voltages and ensures greater noise immunity following start-up. The oscillator circuit, when operated as an RC oscillator, may be operated as a Schmitt-trigger oscillator as soon as the oscillator is turned-on.
    Type: Grant
    Filed: October 31, 1985
    Date of Patent: September 23, 1986
    Assignee: RCA Corporation
    Inventor: Russell G. Ott
  • Patent number: 4370625
    Abstract: In a microcomputer integrated circuit the option of selecting between an RC oscillator or a crystal oscillator for generating the clock for the microprocessor is made available. By making the selection during the manufacturing process, external pin outs and chip area are minimized.
    Type: Grant
    Filed: January 7, 1981
    Date of Patent: January 25, 1983
    Assignee: Motorola, Inc.
    Inventor: Ashok H. Someshwar
  • Patent number: 4190808
    Abstract: An amplifier-oscillator frequency multiplier apparatus utilizing a pair of servo-connected amplifiers which are electronically switchable to provide either a coherent amplifier or a non-coherent oscillator.
    Type: Grant
    Filed: March 23, 1978
    Date of Patent: February 26, 1980
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Lyle A. Fajen
  • Patent number: 4064462
    Abstract: This invention is an acoustic feedback peak elimination unit and has as its objective the elimination of unwanted acoustic resonance peaks, also called ring modes, inherent in an enclosed region where a sound amplifying system may be used. A number of separate units embodying the present invention may be used in cascade, each unit being adapted to handle a small frequency range of about an octave within the entire frequency range to be amplified, each such unit functioning at unity gain to eliminate a single feedback peak when present. In addition, the invention includes means for energizing an oscillator within its tunable frequency range so that a particular frequency may be introduced for tuning the entire sound system with desired precision.
    Type: Grant
    Filed: December 29, 1976
    Date of Patent: December 20, 1977
    Assignee: Dukane Corporation
    Inventors: Rolf J. Goehler, Charles W. King
  • Patent number: 4056787
    Abstract: A self-oscillating mixer circuit suitable for a television receiver is provided using characteristically a single or two switching diodes. During VHF receiving, the mixer circuit operates in a self-oscillating mixing mode under an optimum bias condition, while, during UHF receiving, it operates under an optimum bias condition for intermediate frequency amplification, ceasing its local oscillation.
    Type: Grant
    Filed: May 28, 1976
    Date of Patent: November 1, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Saitoh, Eisaku Akutsu, Mitsuhisa Shinagawa
  • Patent number: 4044317
    Abstract: A crystal controlled square wave oscillator requiring a minimum number of components, exhibiting high frequency stability, and operating at substantially a 50% duty cycle. A quartz crystal dual monolithic resonator is provided having a pair of signal electrodes and a reference electrode. The resonator is capable of oscillating in symmetric and anti-symmetric modes, points of minimum attenuation, the symmetric mode exhibiting a 180.degree. phase shift, and the anti-symmetric mode exhibiting a phase shift of 0.degree.. An integrated circuit logic gate is connected between the signal electrodes, the logic gate being of the type having low input and output impedances so as not to degrade the Q of the resonator. The logic gate provides a phase shift of 180.degree. or 0.degree. causing the resonator to oscillate in its symmetric or anti-symmetric modes, respectively, the gate switching between its two logic levels to produce a square wave output at the frequency of the excited mode.
    Type: Grant
    Filed: October 18, 1976
    Date of Patent: August 23, 1977
    Assignee: CTS Corporation
    Inventors: Darrell E. Newell, John F. Jennings, Steven Lyle Fritsch, Howard D. Hinnah
  • Patent number: 4001732
    Abstract: In a signal compressor wherein an amplified and smoothed control signal is employed to control a variable gain or variable impedance device, a switch is provided to connect a positive feedback loop across the control signal amplifier, thereby to place the compressor in an oscillator mode for providing an alignment or calibration signal of stable amplitude.
    Type: Grant
    Filed: April 9, 1975
    Date of Patent: January 4, 1977
    Assignee: Dolby Laboratories, Inc.
    Inventor: Kenneth James Gundry