Frequency Stabilization Patents (Class 331/41)
  • Patent number: 8873682
    Abstract: A technique to provide hybrid compensation to correct for drifts in a reference frequency output from a digitally-controlled crystal oscillator (DCXO). A first compensation is provided to the DCXO to adjust for overlap or discontinuity of the reference frequency caused by switching capacitors in the capacitor array that controls drift of the reference frequency output. The second compensation is obtained at a phase-locked loop (PLL) that receives the reference frequency signal from the DCXO. The second compensation adjusts the PLL to adjust for variations of the reference frequency that remain after performing compensation in the DCXO.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: October 28, 2014
    Assignee: Broadcom Corporation
    Inventors: Rami Mehio, Masoud Kahrizi, Cobus de Beer, Michael Buyanin
  • Patent number: 8680931
    Abstract: A periodic signal generator is configured to generate high frequency signals characterized by relatively low temperature coefficients of frequency (TCF). This generator may include an oscillator containing a pair of equivalent MEMs resonators therein, which are configured to support bulk acoustic wave and surface wave modes of operation at different resonance frequencies. Each resonator includes a stack of layers including a semiconductor resonator body (e.g., Si-body), a piezoelectric layer (e.g., AIN layer) on the resonator body and interdigitated drive and sense electrodes on the piezoelectric layer. The oscillator is configured to support the generation of first and second periodic signals having unequal first and second frequencies (f1, f2) from first and second resonators within the pair. These first and second periodic signals are characterized by respective first and second temperature coefficients of frequency (TCf1, TCf2), which may differ by at least about 10 ppm/° C.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: March 25, 2014
    Assignee: Integrated Device Technology Inc.
    Inventor: Wanling Pan
  • Patent number: 8497740
    Abstract: A rubidium oscillator or a cesium oscillator is used as a high stability oscillator, and an OCXO being a metastable oscillator which is inferior in a long-term frequency stability compared with the above oscillators but has a high short-term frequency stability is used as a backup. There is prepared a table in which an elapsed time since an occurrence of an abnormality in the high stability oscillator and weighting (use ratio) of use of the both oscillators is corresponded, and by using this table, after the high stability oscillator recovers, an oscillation frequency of the metastable oscillator is used by 100% initially, but thereafter the weighting (use ratio) of use of the metastable oscillator is made smaller and the use ratio of the high stability oscillator is made larger in stages.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: July 30, 2013
    Assignee: Nihon Dempa Kogyo Co., Ltd.
    Inventor: Naoki Onishi
  • Publication number: 20120229220
    Abstract: Disclosed is an oscillator that relies on redundancy of similar resonators integrated on chip in order to fulfill the requirement of one single quartz resonator. The immediate benefit of that approach compared to quartz technology is the monolithic integration of the reference signal function, implying smaller devices as well as cost and power savings.
    Type: Application
    Filed: March 26, 2007
    Publication date: September 13, 2012
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Emmanuel P. Quevy, Roger T. Howe
  • Patent number: 8264284
    Abstract: The present invention relates to an atomic frequency acquisition device comprising a gas cell (400) filled with an atomic gas, a laser light source (100) emitting a laser beam which enters the gas cell (40) and excites a first energy transition of the atomic gas, a local oscillator (700) for generating an oscillator frequency in a frequency range including a frequency of a HFS transition of the atomic gas, and a modulator (600) modulating the laser light source (100) so as to emit laser radiation modulated with the oscillator frequency. An optical reflector (500) is arranged behind the gas cell (400) to reflect the laser beam after passage through the atomic gas so as to re-enter the laser cavity. A photodetector (200) detects beat frequencies caused by self-mixing interference within the laser cavity.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: September 11, 2012
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Holger Moench
  • Patent number: 8242857
    Abstract: A single side band (SSB) mixer includes an in-phase SSB mixer unit and a quadrature-phase SSB mixer unit. The in-phase SSB mixer unit generates an in-phase output current, and includes a first transformer load in which a portion of a quadrature-phase output current flows. The quadrature-phase SSB mixer unit generates the quadrature-phase output current, and includes a second transformer load in which a portion of the in-phase output current flows. The SSB mixer may be used in a wide frequency band without degrading frequency selectivity.
    Type: Grant
    Filed: July 14, 2010
    Date of Patent: August 14, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Kyung-Goo Moh
  • Patent number: 8174328
    Abstract: A dual-band wideband local oscillation signal generator includes an oscillation unit, a division unit, a poly phase filter (PPF), a switch unit, and a single side band (SSB) mixer. The oscillation unit is configured to generate a positive in-phase (IP) signal, a negative in-phase (IN) signal, a negative quadrature-phase (QN) signal, and a positive quadrature-phase (QP) signal. The division unit is configured to divide frequencies of the IP signal and the IN signal and generate an RF signal. The PPF is configured to receive the IP signal and the IN signals inputted to the division unit, and generate an LO IP signal, an LO IN signal, an LO QP signal, and an LO QN signal. The switch unit is configured to receive the generated LO signals and select a high band frequency signal or a low band frequency signal.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: May 8, 2012
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bong-Hyuk Park, Kwang-Chun Lee, Hyun-Kyu Chung
  • Patent number: 8031010
    Abstract: The present invention is a Chip Scale Atomic Clock (CSAC)-enabled Time and Frequency Standard (CTFS) architecture. The CTFS architecture includes a microcontroller, a Time Compensated Crystal Oscillator (TCCO) circuit which is connected to the microcontroller, and a Chip Scale Atomic Clock (CSAC) which is connected to the microcontroller. The microcontroller is configured for selectively causing the CTFS to provide a TCCO circuit-based output frequency when the CTFS has not locked to a predetermined atomic resonance, and is further configured for causing the CTFS to provide a CSAC-based output frequency when the CTFS has locked to a predetermined atomic resonance.
    Type: Grant
    Filed: September 24, 2009
    Date of Patent: October 4, 2011
    Assignee: Rockwell Collins, Inc.
    Inventors: Roy W. Berquist, Robert A. Newgard, Joseph M. Bohl
  • Patent number: 7928807
    Abstract: The present invention provides a frequency synthesizer for a wireless communication system. The synthesizer includes an oscillator that generates an electronic signal as well as frequency dividers, frequency selectors and mixers. The signal generated by the oscillator is sequentially divided by the frequency dividers to produce a first group of frequencies, and the selectors and mixers are then capable of mixing the first group of frequencies according to instructions from control bits to produce a second group of frequencies which constitute UWB band frequencies. In this manner, the synthesizer can generate all 14 UWB band frequencies or particular UWB band groups using a single oscillator. One of the frequencies generated by the dividers can also be used as the baseband clock signal without requiring an additional frequency source.
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: April 19, 2011
    Assignee: QUALCOMM Incorporated
    Inventor: Chinmaya Mishra
  • Patent number: 7805122
    Abstract: A novel and useful apparatus for and method of local oscillator (LO) generation with non-integer multiplication ratio between the local oscillator and RF frequencies. The LO generation schemes presented are operative to generate I and Q square waves at a designated frequency while avoiding the well known issue of harmonic pulling. The signal is input to a synthesizer timed to a rational multiplier of the RF frequency fRF. The signal is then divided to generate a plurality of phases of the divided signal. A plurality of combination signals are generated which are then multiplied by a set of weights and summed to cancel out some undersired products. The result is filtered to generate the LO output signal.
    Type: Grant
    Filed: August 24, 2007
    Date of Patent: September 28, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Gregory Lerner, Nir Tal
  • Patent number: 7773953
    Abstract: Provided is a wireless transceiving apparatus for variability of signal processing band, in which at least one resonator of an analog processor and a VCO are simultaneously controlled using a frequency synthesizer, and a frequency of the VCO and a resonance frequency of the analog processor are controlled to have a rational number ratio, thereby capable of varying the signal processing band. The wireless transceiving apparatus includes: an analog processor having a plurality of resonators on a path of transmission/reception signals, for performing analog signal processing; a digital processor for performing digital signal processing on an output signal of the analog processor or data to be transmitted to the analog processor; and a frequency synthesizer for providing a local oscillation (LO) frequency and a controlling signal to the resonators of the analog processor so as to vary a signal processing band of the analog processor.
    Type: Grant
    Filed: September 12, 2005
    Date of Patent: August 10, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Seon-Ho Han, Mun-Yang Park, Hyun-Kyu Yu, Cheon-Soo Kim
  • Patent number: 7756487
    Abstract: A novel and useful apparatus for and method of local oscillator (LO) generation with non-integer multiplication ratio between the local oscillator and RF frequencies. The LO generation schemes presented are operative to generate I and Q square waves at a designated frequency while avoiding the well known issue of harmonic pulling. The input signal is fed to a synthesizer timed to a rational multiplier of the RF frequency L/N fRF. The clock signal generated is divided by a factor Q to form 2Q phases of the clock at a frequency of L(N*Q)fRF, wherein each phase undergoes division by L. The phase signals are input to a pulse generator which outputs a plurality of pulses. The pulses are input to a selector which selects which signal to output at any point in time. By controlling the selector, the output clock is generated as a TDM based signal. Any spurs are removed by an optional filter.
    Type: Grant
    Filed: August 24, 2007
    Date of Patent: July 13, 2010
    Assignee: Texas Instruments Incorporated
    Inventors: Gregory Lerner, Nir Tal, Robert B. Staszewski
  • Patent number: 7728684
    Abstract: Device and method for temperature compensation in a clock oscillator using quartz crystals, which integrates dual crystal oscillators. The minimal power consumption is achieved through an efficient use of a processor in charge of the synchronization of the two oscillators. The invention is particularly adapted for the provision of a precise reference clock in portable radiolocalization devices.
    Type: Grant
    Filed: September 10, 2007
    Date of Patent: June 1, 2010
    Assignee: QUALCOMM Incorporated
    Inventor: Andrew Tozer
  • Patent number: 7656238
    Abstract: A frequency synthesizing apparatus and method having an injection-locked quadrature VCO in an RF transceiver is provided. In the frequency synthesizer, an I signal following a frequency of a high frequency signal that is input using the injection-locked quadrature VCO and a Q signal thereof are simultaneously generated to have an appropriate driving power. Accordingly, the I signal and the Q signal thereof that are generated in the injection-locked quadrature VCO may be utilized as a local signal for frequency up/down-conversion, without being buffered. An output of an SSB mixer may be directly input into the injection-locked quadrature VCO. Also, high frequency signals that are generated in another circuit such as the SSB mixer, a PLL, or a VCO may be selected to be input into the injection-locked quadrature VCO by a selector.
    Type: Grant
    Filed: June 7, 2006
    Date of Patent: February 2, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chun Deok Suh, Jeong Wook Koh, Hoon Tae Kim
  • Patent number: 7652542
    Abstract: A signal generator generates a first internal signal including frequency f1, a second internal signal including frequency f2, and a third internal signal including frequency f3 twice as high as frequency f2, and selects and delivers one from among a first output signal including frequency f1, a second output signal including frequency f1+f2, and a third output signal including frequency f1+f3, using the first, second, and third internal signals.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: January 26, 2010
    Assignee: NEC Corporation
    Inventor: Noriaki Matsuno
  • Patent number: 7629857
    Abstract: A second harmonic oscillator has a series positive feedback configuration, suppresses output of a fundamental signal, and outputs a second harmonic signal having a frequency in a range from 1 GHz to 200 GHz generated inside of a circuit. The second harmonic oscillator includes: a transistor having a base terminal, a first emitter terminal, a second emitter terminal, and a collector terminal; a resonator circuit connected to the base terminal; a first transmission line shod-circuiting stub connected to one of the two emitter terminals; and a second transmission line short-circuiting stub connected to the other of the two emitter terminals and having a line length obtained by adding one-fourth of one wavelength of the fundamental signal to an integer multiple of one-half wavelength of the fundamental signal.
    Type: Grant
    Filed: February 22, 2008
    Date of Patent: December 8, 2009
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shinsuke Watanabe, Akira Inoue
  • Patent number: 7598815
    Abstract: Multiple carrier frequencies are provided from a phase locked loop, especially closely adjacent quadrature amplitude modulated subcarriers for multiplexed data communications. A quadrature voltage controlled oscillator (VCO) and cascaded frequency dividers provide feedback to a phase comparator to lock the VCO to a reference signal. In addition to frequency divider outputs for use as subcarriers, e.g., binary division factors of the VCO frequency, a quadrature mixer multiplies and adds corresponding quadrature components at two of the frequencies, to generate a differential signal at a difference frequency. The mixer may be outside of the feedback signal path but preferably is in the feedback path to suppress noise. A polyphase filter converts the mixer output to a quadrature signal useful as a subcarrier. The technique efficiently generates sequential integer multiples of a basic frequency, such as sixteen adjacent integer multiples of a frequency reference.
    Type: Grant
    Filed: October 3, 2007
    Date of Patent: October 6, 2009
    Assignee: Agere Systems Inc.
    Inventors: Jinghong Chen, Chunbing Guo, Fuji Yang
  • Patent number: 7545224
    Abstract: A low cost, low phase noise microwave synthesizer includes a DDS modulation circuit and a phase-locked loop. The DDS modulation circuit modulates the output of a DDS to a high frequency. The phase-locked loop downconverts the DDS output and locks the downconverted signal to a relatively low frequency, fixed reference.
    Type: Grant
    Filed: April 12, 2007
    Date of Patent: June 9, 2009
    Assignee: Teradyne, Inc.
    Inventors: Colin Ka Ho Chow, David E. O'Brien
  • Patent number: 7323945
    Abstract: A fully integrated, programmable mixed-signal radio transceiver comprising a radio frequency integrated circuit (RFIC) which is frequency and protocol agnostic with digital inputs and outputs, the radio transceiver being programmable and configurable for multiple radio frequency bands and standards and being capable of connecting to many networks and service providers. The RFIC includes a tunable resonant circuit that includes a transmission line having an inductance, a plurality of switchable capacitors configured to be switched into and out of the tunable resonant circuit in response to a first control signal, and at least one variable capacitor that can be varied in response to a second control signal, wherein a center resonant frequency of the resonant circuit is electronically tunable responsive to the first and second control signals that control a first capacitance value of the plurality of switchable capacitors and a second capacitance value of the at least one variable capacitor.
    Type: Grant
    Filed: February 10, 2005
    Date of Patent: January 29, 2008
    Assignee: BitWave Semiconductor, Inc.
    Inventors: Russell J. Cyr, Geoffrey C. Dawe
  • Patent number: 7075957
    Abstract: An apparatus and method of controlling an optical signal includes superimposing at least one optical reference signal and the optical signal to obtain at least one interference signal having an actual beat frequency, and pre-selecting one or more of the at least one interference signals using a predetermined bandwidth and a filter characteristic that is asymmetric with respect to an actual frequency of the optical signal, to determine a position of the optical signal relative to the at least one optical reference signal.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: July 11, 2006
    Assignee: Agilent Technologies, Inc.
    Inventors: Ulrich Kallmann, Bernd Nebendahl, Wolf Steffens, Emmerich Mueller, Hansjoerg Haisch, Jochen Schwarz
  • Patent number: 7046099
    Abstract: An oscillator having a desired output frequency, comprising a cavity resonator 102 loaded with an anisotropic dielectric material and an oscillator circuit 100 including the cavity resonator 102 as a frequency determining element, the oscillator circuit 100 arranged to operate the cavity resonator 102 at a first frequency in a first mode and at a second frequency in a second mode, the first mode and the second mode each being influenced to a different extent by the thermal coefficient of permittivity of at least one crystal axis of the dielectric material, the oscillator circuit arranged to produce the desired operating frequency from the first frequency and the second frequency. The first frequency and the second frequency differ by an amount corresponding to the desired output frequency.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: May 16, 2006
    Assignees: Poseidon Scientific Instruments Pty Ltd, The University of Western Australia
    Inventors: Eugene Nikolay Ivanov, Michael Edmund Tobar, John Gideon Hartnett
  • Patent number: 6960962
    Abstract: A system and method for generating a local oscillator (LO) frequency in a zero intermediate frequency (IF) receiver or transmitter is presented. A signal is received from a voltage controlled oscillator (VCO). The signal has a VCO frequency. The VCO frequency is divided by a number N to produce a signal having a divided-down frequency. The signal having the VCO frequency is then mixed with the signal having the divided-down frequency to produce an output signal having an output frequency. Local oscillator leakage is reduced. Thus, the receiver or transmitter may operate in multiple wireless communication bands and modes and meet the associated specifications.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: November 1, 2005
    Assignee: Qualcomm Inc.
    Inventors: Paul E. Peterzell, David Maldonado, Kevin Gard, Puay Hoe See, Jeremy Dunworth, Gurkanwal Sahota
  • Patent number: 6733121
    Abstract: The present invention is directed to a method of forming a unitary front face for eyeglasses provided with lenses that have magnifying power.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: May 11, 2004
    Assignee: Contour Optik, Inc.
    Inventor: George W. Chao
  • Patent number: 6731919
    Abstract: Disclosed is an amplifier apparatus that corrects mismatching of the filter transmission characteristic due to a change in the temperature of the amplifier apparatus itself and thereby stably amplifies the high-frequency signal. The amplifier apparatus converts a signal to be processed into one having an intermediate frequency band to thereby execute amplification processing.
    Type: Grant
    Filed: October 11, 2001
    Date of Patent: May 4, 2004
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Takashi Uchida, Masaki Suto, Shoji Fujimoto, Junetsu Urata, Hidefumi Ito
  • Patent number: 6590463
    Abstract: A RC oscillator circuit with a stable output frequency, having an oscillating integrated circuit working under an operation voltage, the resistor, a first capacitor, a second capacitor, and a transistor. The first and second capacitors construct a RC circuit. The resistor has first and second terminals coupled to output and input terminals of the oscillating integrated device, respectively. The first capacitor has first and second terminals coupled to the input terminal of the oscillating integrated device and the second terminal of the resistor, respectively. The second capacitor has first and second terminals coupled to the second terminal of the first capacitor and ground, respectively. The transistor has a gate coupled to the operation voltage, a drain coupled to the first terminal of the second capacitor, and a grounded source. The RC oscillator circuit with a modulable frequency can work under difference operation voltages and output the same frequency.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: July 8, 2003
    Assignee: Faraday Technology Corp.
    Inventor: Han-Tsun Lin
  • Publication number: 20020196088
    Abstract: A microwave synthesizer includes a drift-cancel loop having a narrow-band input, a low-frequency comb input, a wide-band input, and an output for providing an adjustable-frequency output signal. A narrow-band synthesizer is coupled to the narrow-band input, and a comb generator is coupled to the low-frequency comb input. Instead of using a wide-band synthesizer to drive the wide-band input, as conventional topologies have done, the instant invention employs a highly stable, low noise high frequency oscillator. The output of the oscillator is mixed with the output of the comb generator to produce low-noise, high frequency combs. The low-noise, high frequency combs are then used to drive the wide-band input of the drift-cancel loop. Significant reductions in phase noise can be achieved as compared with conventional designs.
    Type: Application
    Filed: June 12, 2001
    Publication date: December 26, 2002
    Inventor: Bernard M. Cuddy
  • Patent number: 6404293
    Abstract: An oscillator circuit is disclosed which includes an oscillator to generate a first signal having a first frequency, a second oscillation source to generate a second signal having a second frequency, the second oscillator comprising a frequency divider coupled to the oscillator, and a mixer to mix to the first and second signals, wherein the oscillator, frequency divider and mixer are each quadrature. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: June 11, 2002
    Assignee: Broadcom Corporation
    Inventors: Hooman Darabi, Ahmadreza Rofougaran, Maryam Rofougaran
  • Patent number: 6194931
    Abstract: Backbias voltage generation circuit corresponding to the frequency of a chip control signal is disclosed. The circuit includes a normal driving unit, an active driving unit and a level detecting unit. The level detecting unit detects whether a backbias voltage VBB is equal to or higher than a target voltage level. A normal control signal DETN is activated to enable the normal driving unit, and an active control signal DETA is activated to enable the active driving unit. The normal driving unit pumps down the backbias voltage VBB independent of the chip control signal CONC. The active driving unit includes a counter circuit and an active pumping unit. The counter circuit generates first and second edge detecting signals FED and RED in response to an activating edge of the chip control signal CONC. The active pumping unit pumps down the backbias voltage VBB, when the first edge signal FED or second edge signal RED is activated.
    Type: Grant
    Filed: April 22, 1999
    Date of Patent: February 27, 2001
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Hong-sun Hwang
  • Patent number: 6163229
    Abstract: A frequency generating circuit scales a warp range of a frequency signal. The frequency generating circuit includes a first frequency signal (10) having a first offset signal with a first frequency relationship to the first frequency signal, and a second frequency signal (14). A frequency scaling element (16) receives the first frequency signal (10) and second frequency signal and provides a third frequency signal, such that the third frequency signal includes the first offset signal having a second frequency relationship to the third signal. A switch (54), has a control input (74), a first input for receiving the first frequency signal, a second input operably coupled to the frequency scaling element (16, 42) for receiving the third frequency signal and an output (76) operably coupled to the first input or the second input dependent upon a control signal applied to the control input (74).
    Type: Grant
    Filed: December 10, 1997
    Date of Patent: December 19, 2000
    Assignee: Motorola, Inc.
    Inventors: Alfred Caspers, Manfred Mueller, Stefan Lichterfeld, Norbert Roettger
  • Patent number: 6151076
    Abstract: A system for phase-locking a clock to a digital audio signal embedded within a digital video signal uses an audio extractor, frequency dividers, and an adjusted bandwidth loop filter to prevent phase jitter associated with the digital audio signal preventing the functionality of the phase-lock loop or having unacceptable effects on the generated audio sample frequency signal. Extracted audio samples are divided down and input to a phase detector. The signal is then filtered using a series of loop filters, one of which has an adjusted bandwidth to reject phase jitter. A clock then outputs the generated synthesized audio sample frequency using the output from the series of loop filters, and the synthesized frequency signal is looped back through a second frequency divider to the phase detector.
    Type: Grant
    Filed: February 10, 1998
    Date of Patent: November 21, 2000
    Assignee: Tektronix, Inc.
    Inventors: Gilbert A. Hoffman, Scott Zink
  • Patent number: 6044333
    Abstract: The invention relates to a device and process for data transmission. The data is transmitted by changes in the field strength of an electromagnetic or magnetic field, and then the times between at least two sequential field strength changes are evaluated. A frequency serving as the time base for evaluating the times between the field strength changes is calibrated at least at the beginning of data transmission so that it has a set relationship to the cycle duration of the field strength changes.
    Type: Grant
    Filed: October 13, 1998
    Date of Patent: March 28, 2000
    Assignee: Anatoli Stobbe
    Inventors: Anatoli Stobbe, Hartmut Scheffler
  • Patent number: 6005446
    Abstract: An apparatus and method for synthesizing low-noise, high stability, multi-frequency microwave signals is disclosed. The output frequencies of a lower frequency, low-noise, synthesizer are upconverted to higher microwave frequencies by mixing these frequencies with the output frequency of an ultra low noise microwave oscillator, determined by a very high Q resonator. Such resonators exhibit large frequency dependence on temperature, but the frequency of an ultra low noise microwave oscillator cannot be stabilized by phase-lock to a stable reference because of its very narrow voltage-controlled frequency tuning range, caused by the very high Q of the resonator. The microwave synthesizer output frequency stabilization is achieved by a novel phase-lock loop which uses the frequency tunability of a low noise SAW oscillator to compensate for the frequency drift of the microwave oscillator.
    Type: Grant
    Filed: October 1, 1997
    Date of Patent: December 21, 1999
    Assignee: Raytheon Company
    Inventors: Zvi Galani, James T. Hanson
  • Patent number: 5847612
    Abstract: An interference free local oscillator circuit is disclosed. A first local oscillator signal is generated in a first phase locked loop. A second local oscillator signal is generated in a second phase locked loop. Third and fourth phase locked loops provide inputs to the second phase locked loop to control the second local oscillator frequency. The operating frequencies of the first and second local oscillator signals are selected so that spurious signals generated in the phase locked loops do not interfere with a received RF signal in a conversion circuit.
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: December 8, 1998
    Assignee: Microtune, Inc.
    Inventor: Vince Birleson
  • Patent number: 5748047
    Abstract: A microwave frequency generator and method of generating a predetermined microwave signal. The invention comprises oscillator means to generate a determinable frequency signal and means responsive to the frequency signal received from the oscillator means to generate a predetermined Intermediate Frequency (IF) signal. The invention further includes means to generate a determinable ultrahigh frequency (UHF) signal, along with means responsive to the IF signal and to a UHF signal to generate a resultant frequency signal. Means responsive to the resultant frequency and to the predetermined frequency signal generated by the oscillator means are further provided to generate the desired predetermined microwave frequency signal.
    Type: Grant
    Filed: August 15, 1996
    Date of Patent: May 5, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Warren E. Guthrie, Gary S. Garbe
  • Patent number: 5625324
    Abstract: The frequencies of N oscillators are summed to provide a signal generator output signal. Because the phase noise power spectral densities of the oscillators add as power, the frequency summed output exhibits a noise degradation over a single oscillator of only 10 log(N). The signal generator is implemented to assure independence of the oscillator noise contributions, with phase locking the oscillators to a common frequency for ease of spurious signal control.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: April 29, 1997
    Assignee: Hughes Electronics
    Inventors: Steve I. Hsu, Stephen D. Taylor
  • Patent number: 5519359
    Abstract: A microwave oscillator with loop frequency conversion to and signal amplification at an intermediate frequency. A high-Q sapphire dielectric resonator is coupled in a frequency conversion loop between a pair of balanced mixers. One mixer comprises a downconversion mixer from an output frequency F.sub.0 to an intermediate frequency F.sub.IF, while the other mixer comprises an upconversion mixer from the intermediate frequency F.sub.IF to the output frequency F.sub.0. The frequency conversion loop additionally includes a low 1/f noise IF amplifier coupled between the mixers. The two mixers receive a local oscillator signal having a frequency F.sub.0 .+-.F.sub.IF from a microwave reference signal generator. In such an arrangement, an output frequency section and an intermediate frequency section is provided. The output frequency section includes the sapphire dielectric resonator and an output power divider while the intermediate frequency section includes the two mixers and the IF amplifier.
    Type: Grant
    Filed: April 26, 1995
    Date of Patent: May 21, 1996
    Assignee: Westinghouse Electric Corp.
    Inventor: Michael M. Driscoll
  • Patent number: 5408201
    Abstract: A frequency synthesizer includes three subfrequency synthesizers: a first synthesizer generating a first subfrequency varying in units of a frequency step, a second synthesizer generating a second subfrequency varying in units of a frequency step being N times the first frequency step, and a third synthesizer generating a third subfrequency varying in units of the first frequency step. One output signal is obtained by mixing the first subfrequency and the second subfrequency. A second output signal is obtained by mixing the second subfrequency and the third subfrequency.
    Type: Grant
    Filed: May 20, 1994
    Date of Patent: April 18, 1995
    Assignee: NEC Corporation
    Inventor: Susumu Uriya
  • Patent number: 5309116
    Abstract: A multimode oscillator is disclosed which employs a single gain loop for exciting at least two modes of a resonator to cause the oscillator to oscillate simultaneously at at least two frequencies. The multimode oscillator comprises the resonator, an amplifier to provide gain at the appropriate operating frequencies to support simultaneous oscillation at such frequencies and an equalizing network with amplitude and phase characteristics versus frequency to support the simultaneous modes of oscillation. The single loop oscillator permits separate control of the two simultaneous different frequencies of oscillation. In order to minimize thermal hysteresis, at least the active portion of the feedback loop does not include inductors. In some applications, the multimode oscillator may include one or more rejection networks to suppress unwanted oscillations. The useful outputs of the multimode oscillator are one or more of the operating frequencies, harmonics and intermodulation products.
    Type: Grant
    Filed: November 2, 1992
    Date of Patent: May 3, 1994
    Assignee: Frequency Electronics, Inc.
    Inventor: Charles S. Stone
  • Patent number: 5160901
    Abstract: A multimode oscillator is disclosed which employs a single gain feedback loop for exciting at least two modes of a resonator to cause the oscillator to oscillate simultaneously at at least two frequencies. The multi-mode oscillator comprises the resonator, an amplifier to provide gain at the appropriate operating frequencies to support simultaneous oscillation at such frequencies and an equalizing network with amplitude and phase characteristics versus frequency to support the simultaneous modes of oscillation. The single loop oscillator permits separate control of the two simultaneous different frequencies of oscillation. In order to minimize thermal hysteresis, at least the active portion of the feedback loop does not include inductors. In some applications, the multimode oscillator may include one or more rejection networks to suppress unwanted oscillations. The useful outputs of the multimode oscillator are one or more of the operating frequencies, harmonics and intermodulation products.
    Type: Grant
    Filed: September 13, 1990
    Date of Patent: November 3, 1992
    Assignee: Frequency Electronics, Inc.
    Inventor: Charles S. Stone
  • Patent number: 4823399
    Abstract: In an RF receiver having a phase-locked loop demodulator and FLL tuning in its RF converter, the frequency of the VCO output signal in the phase-locked loop (PLL) demodulator is controlled indirectly by the FLL in the RF converter in response to a measurement of the VCO output signal in the phase-locked loop demodulator and comparison of such measured signal to a predetermined intermediated frequency. A microcomputer performs a refined FLL tuning algorithm to tune a selected RF carrier input signal and audio subcarrier input signals. The algorithm provides a means of assuring that the PLL demodulator is responding to an input signal derived from a carrier signal of a selected input frequency without having to use hardware to detect the presence of a carrier signal.
    Type: Grant
    Filed: July 30, 1987
    Date of Patent: April 18, 1989
    Assignee: General Instrument Corporation
    Inventor: Ashok K. George
  • Patent number: 4683444
    Abstract: A generator circuit according to the invention generates two 90.degree. phase-shifted frequency-variable sinusoidal signals by mixing the output signal of a fixed-frequency oscillator and of a continuously variable oscillator with the aid of two multipliers operating as mixers. The fixed-frequency signal is applied to the second multiplier via a 90.degree. phase shifter. The output signal of the multipliers which contains the sum and the difference frequency of its input signals, is respectively fed to a low-pass filter or to a band-pass filter, which suppresses the sum frequency or the difference frequency respectively. By the 90.degree. phase shifter, the sinusoidal signal is phase-shifted with respect to the sinusoidal signal by exactly 90.degree.. During the continuous variation process, the signal as applied to the 90.degree. phase shifter remains stable in its frequency, whereas the output signal of the continuously variable oscillator as fed directly to the two multipliers, is changed in its frequency.
    Type: Grant
    Filed: December 13, 1985
    Date of Patent: July 28, 1987
    Assignee: Deutsche ITT Industries GmbH
    Inventor: Otmar Kappeler
  • Patent number: 4510463
    Abstract: A frequency discriminator having a wide capture band is shown to comprise, in addition to a conventional phase detector having two channels fed by a signal whose frequency is to be determined (the first one of the channels containing a tuned circuit operative to shift the phase of the signal in accordance with the difference between the frequency of the signal and the center frequency of the tuned circuit and the second one of the channels containing a phase shifter operative to shift the phase of the signal by 90.degree. regardless of the frequency of the signal), a compensating circuit operative substantially to equalize the amplitudes of the signals applied to the phase detector, the compensating circuit including an amplifier in the first one of the channels to amplify the signal out of the tuned circuit, the gain of the amplifier being controlled by a signal indicative of the difference between the amplitudes of the signals fed to the phase detector.
    Type: Grant
    Filed: April 22, 1983
    Date of Patent: April 9, 1985
    Assignee: Raytheon Company
    Inventors: Zvi Galani, Raymond C. Waterman, Jr.
  • Patent number: 4338575
    Abstract: An arrangement for temperature compensating transducers including two elastic surface wave oscillators whose frequencies are mixed to produce an output frequency that is a function of a parameter to be measured such as force, pressure or acceleration. A delay element such as a transmission line having a delay that is a function of temperature is inserted into the loop of at least one of the oscillators to balance oscillator frequency deviations resulting from temperature changes.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: July 6, 1982
    Assignee: Thomson-CSF
    Inventor: Pierre Hartemann
  • Patent number: 4270100
    Abstract: The microwave oscillator is formed by a free oscillator 1 coupled with two surface or volume acoustic wave delay lines 9 and 10 connected in series or in parallel and operating by reflection. The first line imposes a delay 2.tau..sub.1, corresponding to one reciprocation, which is a multiple of the delay 2.tau..sub.2 imposed by the second line, and a=.tau.1/.tau.2 is preferably equal to 2 or 3. Application to oscillators operating at ultra-high frequencies, particularly in the L-band.
    Type: Grant
    Filed: April 12, 1979
    Date of Patent: May 26, 1981
    Assignee: Thomson-CSF
    Inventors: Jean-Pierre Bergero, Yves Charlet, Philippe Leschaeve
  • Patent number: 4245193
    Abstract: An oscillation control circuit in which the output of an unstabilized oscillator is controlled using a bulk acoustic wave resonator. The circuit includes a high and low frequency loop with the power output of the oscillator being divided and supplied along respective paths to the high and low frequency portions of the loop. The high frequency portion of the loop, which includes the BAW resonator, operates at the output frequency f.sub.0, which is equal to the sum of the oscillator frequency f.sub.1 and the frequency f.sub.2 of the low frequency portion of the loop. A first mixer receives the frequencies f.sub.0 and f.sub.1 and produces an output f.sub.2 in the low frequency portion of the loop, while a second mixer receives the frequencies f.sub.1 and f.sub.2 and produces an output f.sub.0 in the high frequency portion of the loop. In this way, as the oscillator output frequency f.sub.1 varies, the frequency f.sub.
    Type: Grant
    Filed: August 9, 1978
    Date of Patent: January 13, 1981
    Assignee: Harris Corporation
    Inventors: Jing-Jong Pan, Milton P. Arnold
  • Patent number: 3974457
    Abstract: The present invention relates to a time and frequency control unit which is apable of compensating for long-term crystal oscillator drift and other errors in a reference oscillator signal by both coarse and fine (vernier) controlling. The invention takes the reference oscillator frequency, f.sub.o, divides it by a controlled factor a and mixes f.sub.o with f.sub.o /a to produce an f.sub.o + f.sub.o /aSignal. The f.sub.o + f.sub.o /aSignal is then divided by a second controlled factor b and mixed again with f.sub.o to yield a signal of frequency f.sub.o .+-. (f.sub.o + f.sub.o /a) 1/b,Where f.sub.f, the final output frequency, is determined after a filter stage sets the operation sign of the above expression (to plus or minus). Where f.sub.f is intended to be constant with a changing f.sub.o, the values of a and b are changed. From the above expression, it is apparent that a change in a makes a fine correction whereas a change in b translates the frequency with a coarse adjustment.
    Type: Grant
    Filed: September 19, 1975
    Date of Patent: August 10, 1976
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Alvin G. Bates, Terrence L. McGovern