Cyclic Frequency Sweeping Means (e.g., Vibrato) Patents (Class 331/178)
  • Patent number: 8981858
    Abstract: An apparatus includes a selection device to select a spreading profile from a plurality of spreading profiles, and an oscillation device to generate clock signals having different frequencies over time based on the selected spreading profile. A method includes selecting a spreading profile from a plurality of spreading profiles, and generating clock signals having different frequencies over time based on the selected spreading profile.
    Type: Grant
    Filed: December 30, 2011
    Date of Patent: March 17, 2015
    Assignee: Cypress Semiconductor Corporation
    Inventors: David G Wright, Timothy Williams, Edward L. Grivna, Mohandas Palatholmana Sivadasan
  • Patent number: 8441217
    Abstract: With an oscillator circuit with a frequency sweep function, a first counter counts a reference clock for a number of counts that corresponds to a digital first setting signal, and generates a first count completion signal which is asserted on completion of the count. A D/A converter converts a digital second setting signal into an analog control voltage. A VCO oscillates with a frequency according to the control voltage. When the first count completion signal is asserted, the VCO is reset. An output combining unit receives the output signal of the VCO, generates the output signal of the oscillator circuit, and generates the first setting signal and the second setting signal.
    Type: Grant
    Filed: August 9, 2010
    Date of Patent: May 14, 2013
    Assignee: Rohm Co., Ltd.
    Inventor: Hisashi Sugie
  • Patent number: 7843278
    Abstract: A frequency jitter generation circuit having a voltage generator and an oscillator circuit is provided. The voltage generator receives an input voltage and converts the input voltage into an upper reference voltage output to the oscillator circuit. Voltage level of the upper reference voltage is varying. The oscillator circuit is coupled with the voltage generator. Voltage level of a reference voltage in the oscillator circuit is oscillated between the upper reference voltage and a lower reference voltage to generate a frequency signal with a jitter based on the variation of the upper reference voltage.
    Type: Grant
    Filed: September 11, 2008
    Date of Patent: November 30, 2010
    Assignee: Niko Semiconductor Co., Ltd.
    Inventor: Te-Hsien Hsu
  • Patent number: 7791426
    Abstract: A clock frequency modulator for an oscillator having a digital circuit for the generation of a signal modulating the clock frequency, the digital circuit adapted to obtain, from the signal generated by the oscillator, a first pulse signal having a lower frequency than the clock frequency of the oscillator, a digital counter adapted to count the pulses of the first signal and to produce a digital signal and a digital-to-analog converter adapted to convert the digital signal in the signal for modulating the clock frequency of the oscillator.
    Type: Grant
    Filed: May 8, 2008
    Date of Patent: September 7, 2010
    Assignee: STMicroelectronics S.r.l.
    Inventors: Andrea Rapisarda, Filippo Marino, Angelo Maria D'Arrigo
  • Patent number: 7521986
    Abstract: Noise generation is reduced further. Oscillation control circuit 11 generates a modulation signal modulating oscillation frequency of an oscillation signal generated by oscillation circuit 12 and outputs modulation signal to same. Preferably, the modulation signal fluctuates period of the oscillation signal sequentially. The oscillation circuit 12 is composed of a ring oscillator, for example, and the power supply voltage or power supply current of the ring oscillator is controlled to fluctuate sequentially by the modulation signal output from the oscillation circuit 11. Buffer 14 of charge pump circuit 13 generates signals /? and ? by the oscillation signal and drives capacitors C1 and C2 for supplying a higher voltage than the voltage of the power supply Vcc to gate of N-channel MOSFET Q1.
    Type: Grant
    Filed: June 14, 2007
    Date of Patent: April 21, 2009
    Assignee: NEC Electronics Corporation
    Inventor: Tsuyoshi Mitsuda
  • Patent number: 7365608
    Abstract: A single chip digital frequency synthesiser (1) for synthesising a frequency swept synthesised output signal of a selectable frequency sweep comprises a direct digital synthesiser (5) which produces the frequency swept synthesised output signal on an output terminal (7) in response to values of a frequency control digital word applied to a frequency control input (8) thereof by an on-chip data processing circuit (25). An on-chip programmable data storing circuit (12) is programmable to store data indicative of a selected mode in which the digital frequency synthesiser (1) is to operate, and to store data indicative of selectable frequency and the time domains of the frequency swept synthesised output signal to be produced.
    Type: Grant
    Filed: December 8, 2005
    Date of Patent: April 29, 2008
    Assignee: Analog Devices, Inc.
    Inventor: Hans Juergen Tucholski
  • Patent number: 6898262
    Abstract: An output cycle of a pulse string generated from a pulse generating section (2) is divided by a pulse dividing section (3) and a signal having a cycle which is plural times as great as the cycle of an output pulse is output from the pulse dividing section (3). This signal is input as an interruption request signal to a CPU (1). Consequently, the CPU (1) can execute an interruption processing in a cycle which is plural times as great as the cycle of the output pulse. By the interruption processing, the number of pulses to be output is controlled.
    Type: Grant
    Filed: August 10, 2000
    Date of Patent: May 24, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Shinsuke Yokokawa
  • Patent number: 6737904
    Abstract: A method of producing a clock signal with reduced electromagnetic interference spectral components includes providing a first clock signal; producing a second clock signal by delaying the first clock signal; and generating a jittered clock signal by switching between the first clock signal and the second clock signal at times selected responsive to a random number generator.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: May 18, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Remi Butaud, Bernard Ginetti
  • Patent number: 6577203
    Abstract: This invention provides a voltage controlled oscillator that improves the linearity of frequency variable characteristics and increases the range of frequency that can be varied by a control voltage. A resistor circuit is connected between a piezoelectric resonator X and an oscillator circuit. The resistor circuit includes a plurality of oscillation-amplitude adjusting resistors Rs1 to Rsn and corresponding switches SW1 to SWn. The resistor circuit adjusts the amplitude of oscillation. When a control voltage Vc applied to a varactor Cv is at a low potential, clipping by a forward voltage of the varactor Cv is suppressed, and the frequency is linearly changed by the control voltage Vc within a range of a low potential to a high potential.
    Type: Grant
    Filed: August 9, 2001
    Date of Patent: June 10, 2003
    Assignee: Seiko Epson Corporation
    Inventors: Yoichi Fujii, Hiroshi Kinoshita, Takashi Endo
  • Patent number: 6545634
    Abstract: A method for detecting and correcting non-linearities in radio-frequency, voltage controlled oscillators provides for digitization of the frequency signal by feeding the undelayed frequency signal and a delayed frequency signal generated therefrom into EXOR gates. The digital pulses produced thereform are converted using a low pass filter into a proportional DC voltage value which is proportional to the oscillator frequency and is used as a basis for producing a correction value for the frequency control of the oscillator.
    Type: Grant
    Filed: August 17, 2001
    Date of Patent: April 8, 2003
    Assignee: Siemens Aktiengesellschaft
    Inventors: Patric Heide, Matthias Huschenbett, Martin Kunert, Richard Roskosch
  • Patent number: 6252464
    Abstract: An inexpensive numerically-controlled fast frequency-hopping microwave synthesizer. A voltage-controlled oscillator (VCO) output phase remains locked to an internal direct digital synthesizer (DDS) reference signal over the entire output frequency band, which is an order of magnitude larger than the internal sampling clock frequency. A “Nyquist-boundary hopping” scheme compares signals from an alias band of the DDS with signals from an alias band of the sampled VCO output to derive an output phase error signal, which is forced to zero in a manner that locks the VCO output phase to the DDS output phase over a frequency hop-distance greater than the DDS bandwidth. Accordingly, in a single second, the synthesizer can hop phase-continuously in a single clock cycle to each of hundreds of thousands of different microwave output frequencies with relatively low clock rates (up to 100 MHz) commensurate with silicon application-specific integrated circuits (ASICs).
    Type: Grant
    Filed: October 6, 1999
    Date of Patent: June 26, 2001
    Assignee: Cubic Defense Systems, Inc.
    Inventors: Wayne Edward Richards, Jeffrey Morris Keefer
  • Patent number: 6014063
    Abstract: A system of spreading the energy of higher harmonic frequencies in digital circuits to lower the interference to bandpass receivers is disclosed. A set of passive, impedance-regulated circuits, preferably housed in a standard enclosure, comprises a power restoring unit, a modulating signal generator, an internal oscillator and an impedance spreading unit. The circuits are equivalent to passive resonators such as crystal resonators used in standard oscillators. Any existing standard oscillator that uses common crystal resonators can be transformed into a spectrum-spread oscillator by replacing the crystal resonator with the disclosed circuit, whereby a tightly controlled small frequency spreading occurs in the fundamental clock frequency. Further an active oscillator is disclosed wherein a spreading circuit spreads the frequency of the clock signal originally generated by the oscillator based on a sequence of processing the original clock signal.
    Type: Grant
    Filed: August 27, 1997
    Date of Patent: January 11, 2000
    Assignee: Quiet Solutions, Inc.
    Inventors: Dongtai Liu, Mohammed A. Safai
  • Patent number: 5834979
    Abstract: The output of a voltage-controlled oscillator (VCO), after being passed through a resonator having a single-peak characteristic, is detected by a detector. The output of the detector is sampled and held at a time instant that the control input voltage to the VCO reaches a maximum and also at a time instant that it reaches a minimum, and the difference between them is fed back to the control input of the VCO. In this way, the center frequency of the VCO is controlled so that it becomes equal to the center frequency of the resonator. In the case of a VCO as an FM modulator in an FM-CW radar, the sample-and-hold timing is derived from a clock signal based on which a triangle wave is generated. In the case of a VCO as an FSK modulator, the sample-and-hold timing is obtained by detecting a 0 and a 1 in input data.
    Type: Grant
    Filed: August 20, 1997
    Date of Patent: November 10, 1998
    Assignee: Fujitsu Limited
    Inventor: Hiroyuki Yatsuka
  • Patent number: 5805000
    Abstract: A regulating circuit for a quartz crystal oscillator-based timepiece is capable of compensating for large deviations in oscillation frequency of the quartz crystal oscillator. A frequency divider sequentially divides the reference clock by one-half. A regulation data setting circuit sets logical regulation data used to compensate for deviations in the oscillation frequency of the oscillator from a desired value. A regulation circuit adjusts the frequency dividing ratio of the frequency dividing circuit based on the logical regulation data in accordance with a predetermined cycle and controls in such a manner that the frequency of a divided output signal of the frequency divider has a predetermined frequency. When the frequency of the divided output signal cannot coincide with the predetermined frequency using the set logical regulation data, the range of adjustment is shifted using data set in a switch during production of the timepiece.
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: September 8, 1998
    Assignee: Seiko Instruments Inc.
    Inventor: Kazuo Kato
  • Patent number: 5557241
    Abstract: An ultra-linear chirp generator includes a voltage controlled oscillator (VCO) having a tuning characteristic which is naturally nonlinear, a linear ramp generator which generates a linearly ramping output signal having a linear slope characteristic with respect to time, a polynomial correction waveform generator which generates a polynomial correction signal, and a summer which is responsive to and sums the linearly ramping output signal and the polynomial correction signal. The summer generates a VCO tuning signal for tuning the VCO. The tuning signal corresponds to the linearly ramping output signal predistorted with a nonlinearity opposite to the natural nonlinearity of the VCO tuning characteristic. The linear chirp generator also includes a phase locked loop which is responsive to the output signal of the VCO and which has a reference frequency which is related to the repetition rate of the output signal of the VCO.
    Type: Grant
    Filed: May 24, 1995
    Date of Patent: September 17, 1996
    Assignee: AIL Systems, Inc.
    Inventor: Peter J. Burke
  • Patent number: 5521532
    Abstract: A signal source provides an output signal which can sweep over a broad frequency range in a well-controlled manner. The signal source includes a voltage controlled oscillator (VCO) producing the output signal and a waveform synthesizer producing a reference signal. The VCO output signal is phase locked to the reference signal. To make the VCO signal continuously sweep over a broad frequency range, the reference signal sweeps repeatedly over a narrow frequency range. During each sweep of the reference signal, the VCO frequency tracks an integer harmonic of the reference signal frequency. The frequency and phase of the reference signal for each successive sweep are abruptly reset at the beginning of each sweep selected such that the VCO signal frequency locks to another integer harmonic of the reference signal frequency and does not change.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: May 28, 1996
    Assignee: Tektronix, Inc.
    Inventor: Linley F. Gumm
  • Patent number: 5379001
    Abstract: A closed loop linearizer method and apparatus for providing a linear ramp modulation for a voltage controlled oscillator (VCO). A counter is connected to the VCO for calculating two frequency values of the oscillator at one or more time points during a ramp interval. The difference of the two frequency values is then compared with that of a predetermined ideal difference frequency value. A resulting correction value is then generated and used to adjust digital control values upward and downward, thereby causing the VCO to produce a linear modulation ramp output slope over time.
    Type: Grant
    Filed: October 25, 1993
    Date of Patent: January 3, 1995
    Assignee: Alliant Techsystems Inc.
    Inventor: Neil G. Hedtke
  • Patent number: 5374903
    Abstract: A low-frequency low bandwidth Linear Frequency Modulation (LFM) waveform, nominally a 1 MHz to 10 Mz swept frequency analog sinusoid or digital square wave, is produced by direct digital synthesis. This waveform is upconverted in frequency and expanded in bandwidth, nominally to microwave frequencies with bandwidths of nominally 160-360 MHz, in a multiplying offset phase locked loop. The phase locked loop also linearly frequency modulates a X-band carrier with the microwave frequency LFM waveform to produce an output signal suitable for Synthetic Aperture Radar. The phase locked loop induces low phase error, and may be closed around the radar transmitter to remove phase errors induced by that unit.
    Type: Grant
    Filed: April 22, 1988
    Date of Patent: December 20, 1994
    Assignee: Hughes Aircraft Company
    Inventor: James L. Blanton
  • Patent number: 5225794
    Abstract: A method and apparatus for a sweep oscillator and a spectrum analyzer containing the sweep oscillator having a precisely determined center frequency includes a sweep circuit having a sawtooth waveform, a reference oscillator, a microprocessor controller and a modified phase-locked loop. The modified phase-locked loop further includes a control signal summer, a voltage controlled oscillator coupled to the control signal summer, a sweep oscillator output, and a sample and hold circuit including a switching circuit.
    Type: Grant
    Filed: November 18, 1991
    Date of Patent: July 6, 1993
    Assignee: Motorola, Inc.
    Inventors: Robert J. Skalka, Mark J. Brown, Karl C. Stambaugh
  • Patent number: 5210539
    Abstract: A circuit for generating an output signal having an output frequency that varies linearly with time, and to an FM CW radar system utilizing such a circuit. The circuit includes a voltage controlled oscillator that produces an output signal at its output terminal at an output frequency that corresponds to the voltage of an input tuning signal. A comparison signal circuit receives the output signal and produces a periodic comparison signal such that when the output frequency varies by .DELTA.f, the comparison signal frequency varies by .DELTA.f/N where N is a positive integer. An update counter periodically causes the value of N to change by a predetermined integer amount. A phase detector compares the comparison signal to a periodic reference signal, and produces a correction signal that is filtered to provide the tuning signal for the VCO. The value of N is preferably changed at an update frequency that is equal to the frequency of the reference signal times an integer.
    Type: Grant
    Filed: September 30, 1986
    Date of Patent: May 11, 1993
    Assignee: The Boeing Company
    Inventor: Kenneth G. Voyce
  • Patent number: 5210719
    Abstract: An apparatus and method utilizing a sweep-frequency, high voltage generator coupled to an applicator gun for feeding electric power into pest-infested dielectrics, for example termite-infested wood. Utilizing a conventional line frequency of 120 or 60 Hz, the generator produces 140 kilovolts propagated within a spectral band ranging from 15 to 120 kHz and rich in harmonics. Output is discharged through a high-voltage energy storage capacitor charged using an insulated gate bipolar transistor driven by a variable frequency inductively coupled multivibrator. The output voltages penetrate dielectrics and electrocute the pests inside. The invention is effective against insects having hard exoskeletons comprised substantially of cuticulin, chitin, and sclerotin.
    Type: Grant
    Filed: November 12, 1991
    Date of Patent: May 11, 1993
    Assignee: Daniel J. Bondy
    Inventor: Lucas G. Lawrence
  • Patent number: 5175509
    Abstract: Linearizing circuitry for an FMCW transmitter (1,2) employing a linear modulation waveform. The output signal is sampled (3,4,5) in successive intervals, small compared to the modulation period, and a cycle count (16) taken in each interval; a reference count is derived for each interval, either by way of a look-up table (21) triggered by a clock count (17) or derived by way of a clock driven processor (18). A comparison (20) is made and any error (22) is used to control (11) the phase of the modulation waveform.
    Type: Grant
    Filed: March 16, 1992
    Date of Patent: December 29, 1992
    Assignee: Gec-Marconi Limited
    Inventor: Kevin B. Taylor
  • Patent number: 5028886
    Abstract: A swept synthesizer signal source provides a digital synchronization signal for accurate internal synchronization of events and for external synchronization of data taking and other operations to predetermined frequencies generated by an oscillator during a sweep. The digital synchronization signal includes a predetermined number of digital pulses, regardless of the sweep time. A ramp voltage which controls the oscillator is corrected during a calibration period to sweep between predetermined limits, thereby insuring that the ramp voltage is synchronized to the digital synchronization signal. The slope of the frequency versus time sweep is also corrected to further improve accuracy. A power level correction technique insures precision power leveling regardless of the sweep range. A table of correction/frequency pairs is entered into the instrument, and an interpolation algorithm is employed to determine corrections at frequencies corresponding to each synchronization pulse.
    Type: Grant
    Filed: September 29, 1989
    Date of Patent: July 2, 1991
    Assignee: Hewlett-Packard Company
    Inventors: Michael J. Seibel, Douglas E. Fullmer
  • Patent number: 4931749
    Abstract: A frequency synthesizer is provided in which the output is a truly continuous sweep of frequency, not a staircase of spot frequencies. A programmable frequency divider PD is connected to the output of a voltage-controlled oscillator (VCO) to divide the VCO output by a variable integer N. At each VCO output cycle, the integer N is incremented (or decremented). The output of a phase comparator PC, which compares the divider output with a fixed reference frequency, is connected via an integrator (10) to the VCO frequency control input (2). A constant phase error produces a ramp rise of VCO frequency.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: June 5, 1990
    Assignee: U.S. Philips Corporation
    Inventor: Nigel J. Walters
  • Patent number: 4901034
    Abstract: In a process and a circuit for exciting an ultrasonic generator the latter is excited by an output signal of a voltage-controlled oscillator, which is controlled by a control device including a triangular wave generator so that its frequency is periodically swept in a range covering the series resonance of the ultrasonic generator. A measured quantity value, which can be voltage or current corresponding to the damping of the ultrasonic generator, is formed and is compared with the maximum permitted damping. If the established damping is smaller than the maximum permitted damping, the oscillator is additionally regulated as a function of the measured quantity. This measured quantity is preferably a function of the exciting current of the ultrasonic generator. An instantaneous measured value and a delayed value are formed and their difference is compared with a threshold value in a comparator. If this difference is the same as the threshold value, the sweep direction in the control device is reversed.
    Type: Grant
    Filed: April 28, 1989
    Date of Patent: February 13, 1990
    Assignee: Satronic, AG
    Inventor: Jagdt Frank-Peter
  • Patent number: 4855690
    Abstract: An integrated circuit random number generator which uses a triangular output analog oscillator to vary the frequency of a higher frequency voltage controlled oscillator. The output of the voltage controlled oscillator is sampled at a rate much less than the rate of oscillation of the voltage controlled oscillator to produce random digital values.
    Type: Grant
    Filed: November 1, 1988
    Date of Patent: August 8, 1989
    Assignee: Dallas Semiconductor Corporation
    Inventor: Donald R. Dias
  • Patent number: 4810975
    Abstract: A random number generator designed for use with an electronic key uses a triangular output analog oscillator to vary the frequency of a higher frequency voltage controlled oscillator. The output of the voltage controlled oscillator is sampled at a rate much less than the rate of oscillation of the voltage controlled oscillator to produce random digital values.
    Type: Grant
    Filed: August 10, 1987
    Date of Patent: March 7, 1989
    Assignee: Dallas Semiconductor Corp.
    Inventor: Donald R. Dias
  • Patent number: 4797637
    Abstract: A PLL frequency synthesizer comprises a voltage controlled oscillator which oscillates in response to a frequency signal corresponding to a control signal to be input and which outputs the frequency signal as an output of said PLL frequency synthesizer; a multiplier means for multiplying a reference frequency signal to be input; a mixer for mixing the frequency signal which is output from the voltage controlled oscillator and the multiplied reference frequency signal which is output from the multiplier, and for outputting a frequency signal representative of a difference therebetween; a variable frequency divider for dividing the difference frequency signal at a variable dividing ratio; a fixed frequency divider for dividing the reference frequency signal at a predetermined dividing ratio; a frequency phase comparator for detecting a phase difference between an output signal from the variable frequency divider and an output signal from the fixed frequency divider and for outputting a phase difference signal t
    Type: Grant
    Filed: August 24, 1987
    Date of Patent: January 10, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Koyo Kegasa, Takafumi Murai, Osamu Yamanaka, Takeshi Fujii
  • Patent number: 4728906
    Abstract: A signal generating device and method of control thereof for producing a desired output frequency, the generator having coarse and fine tuning controls capable of producing frequency changes over a limited range, wherein the output of the device is combined in a mixing device with a multi-component reference signal produced from an oscillatory generator circuit, a beat signal is detected by processing circuitry as the frequency controls are adjusted and the values of the frequencies of the control signals occurring on such detection are stored, and using a look-up table or algorithm the value of a correction signal is determined which, when combined with the stored values, will cause the output frequency of the device to be adjusted to the desired value via the fine tuner.
    Type: Grant
    Filed: October 15, 1986
    Date of Patent: March 1, 1988
    Assignee: Wiltron Measurements Limited
    Inventors: Christopher B. D. Turl, Geoffrey J. Hurst
  • Patent number: 4695809
    Abstract: A microwave frequency oscillator capable of being linearly swept over a wide frequency range around a central frequency comprising a field-effect transistor with a high gain, the output of which is fed back to the input from a coupler consisting of two relatively narrow striplines located close together. A wobbulator circuit is fitted in shunt to the feedback network comprises two voltage variable capacitors in series between three line components designed to optimize the frequency modulation linearity in relation to the voltage variable capacitance diode control voltage. The oscillator is useful in equipment requiring extreme linearity such as radio-altimeter sources.
    Type: Grant
    Filed: May 23, 1986
    Date of Patent: September 22, 1987
    Assignee: U.S. Philips Corporation
    Inventor: Marie-Irene Rudelle
  • Patent number: 4647873
    Abstract: An apparatus and method for generating an output signal having portions thereof being linearly swept in frequency. A controller, responsive to external signals, generates a series of control signals. An oscillator, responsive to each one of the control signals, produces an output signal. The output signal includes a series of output waveforms each linearly swept in frequency and corresponding to a respective one of the control signals. A first servo, responsive to each one of the output waveforms, produces a series of first correction signals each dependent upon the linearity error in a corresponding one of the output waveforms. The first correction signals modify a corresponding control signal as applied to the oscillator so as to correct linearity errors occurring in a corresponding one of the output waveforms. A second servo, responsive to each one of the first correction signals, produces a series of second correction signals each dependent upon the correlations in the first correction signals.
    Type: Grant
    Filed: July 19, 1985
    Date of Patent: March 3, 1987
    Assignee: General Dynamics, Pomona Division
    Inventors: Frederick L. Beckner, Garry N. Hulderman, Darrell K. Ingram
  • Patent number: 4616191
    Abstract: A frequency-agile source of microwave frequency signals is shown to include: a voltage-controlled oscillator operating within a band of microwave frequencies; a crystal-controlled oscillator operating at a frequency lower than the band of microwave frequencies and producing harmonics within such band; a phase detector having samples of the signals out of the crystal-controlled oscillator and the voltage-controlled oscillator applied as input signals; and a shaping amplifier receiving the output signal of the phase detector to provide a control signal related to the phase difference between the signal out of the voltage-controlled oscillator and the harmonic of the crystal-controlled oscillator nearest to the frequency of the voltage-controlled oscillator.
    Type: Grant
    Filed: July 5, 1983
    Date of Patent: October 7, 1986
    Assignee: Raytheon Company
    Inventors: Zvi Galani, Richard A. Campbell
  • Patent number: 4603305
    Abstract: A method and apparatus for generating a sweep signal, the frequency of which is accurately known at all times during the sweep cycle. The beginning and ending frequencies are fixed by a phase-locked loop and the resulting error correction voltages are stored. During the sweep, these error voltages determine the offset and slope of the D.C. voltage ramp signal which governs the frequency of the sweep oscillator.
    Type: Grant
    Filed: July 24, 1984
    Date of Patent: July 29, 1986
    Assignee: Cushman Electronics, Inc.
    Inventor: Earl McCune
  • Patent number: 4560960
    Abstract: A digital device generating a frequency-modulated signal. The device comprises a programmable divider which divides the frequency f.sub.H of the clock by a variable integer N supplied by a control circuit. The output pulse signal of the frequency divider initiates the supplying of the next value of N by the control circuit. A shaping circuit brings the pulse signal into the form of a signal whose half-cycles successively have a duration equal to an integer multiple N of the clock period 1/f.sub.H. A supplementary circuit makes it possible to improve the precision of the modulation obtained compared with the desired phase by optionally delaying each half-cycle of the modulated signal by a fraction of the block period. The present invention is applicable to radar and telemetry.
    Type: Grant
    Filed: February 24, 1983
    Date of Patent: December 24, 1985
    Assignee: Thomson CSF
    Inventor: Jean Claude Chanrion
  • Patent number: 4554516
    Abstract: An electronically tunable solid-state microwave frequency source comprises a transmission-absorption filter incorporated within a magnetic structure. The transmission-absorption filter is employed with a tunable solid-state oscillator and tunable solid-state multiplier to provide a continuously tunable microwave signal source with enhanced spurious signal attenuation over a multiple-octave tuning range. The filter structure comprises a sphere of monocrystalline garnet such as yttrium iron garnet (YIG) and two coupling loops disposed in the field region of an adjustable field DC magnet. The coupling loops are disposed orthogonal to the magnetic field and to each other. In a specific embodiment the first coupling loop is operative to receive at its input the fundamental frequency signal and at its output is grounded, and the second coupling loop is operative to receive a harmonic input signal at its input and to convey a desired output signal at its output.
    Type: Grant
    Filed: November 29, 1984
    Date of Patent: November 19, 1985
    Assignee: Microsource, Inc.
    Inventor: Ganesh R. Basawapatna
  • Patent number: 4546328
    Abstract: A phase-locked voltage controlled oscillator for generating frequency modulated waveforms having a programmable digital RF phase shifter to determine the phase difference between the output signal and a phase corrected reference signal to thereby generate the desired output waveform.
    Type: Grant
    Filed: May 23, 1983
    Date of Patent: October 8, 1985
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Edwin B. Smith, John R. Fogleboch, Sr.
  • Patent number: 4518932
    Abstract: A co-axial magnetron is provided with a cavity whose resonant frequency can be very rapidly altered in a cyclic manner so that the microwave output frequency of the magnetron can be chosen to lie within the available frequency band of the cavity. The cylindrical walls of the co-axial resonant cavity are constituted by or coupled to the inner surfaces of one or more tuning forks which are maintained in vibration by externally mounted electro-magnetic transducers. As the tines of the tuning forks vibrate, the effect is to cyclically increase and decrease the effective diameter of the cavity, thereby changing its resonant frequency. An adjustable end plate can be provided for the cavity so that fine tuning or slow rate tuning can be provided in addition to the frequency agility provided by the tuning fork.
    Type: Grant
    Filed: August 10, 1982
    Date of Patent: May 21, 1985
    Assignee: English Electric Valve Company, Ltd.
    Inventor: Alan H. Pickering
  • Patent number: 4513256
    Abstract: A sweep voltage from a sweep voltage generator is provided to sweep start and stop adjusting means, the outputs of which are summed by a summing circuit and, by the summed output, the oscillation frequency of a voltage controller oscillator is controlled. The oscillation frequency of the voltage controlled oscillator and the output frequency of a reference signal generator set to a sweep start frequency are compared by comparing means. The output of the sweep voltage generator is put in a sweep start state and sweep start adjusting means is adjusted in accordance with the output of the comparing means, thereby to cause the oscillation frequency of the voltage controlled oscillator to agree with a set sweep start frequency. The output of the sweep voltage generator is put in a sweep stop state and sweep stop adjusting means is adjusted in accordance with the output of the comparing means, thereby to cause the oscillation frequency of the voltage controlled oscillator to agree with a set sweep stop frequency.
    Type: Grant
    Filed: June 29, 1983
    Date of Patent: April 23, 1985
    Assignee: Takeda Riken Co., Ltd.
    Inventors: Takenori Kurihara, Shigeki Tojo, Yohei Hirakoso
  • Patent number: 4499435
    Abstract: Non-linearities in the sweep output of a voltage controlled oscillator are automatically linearized by a scheme that compensates for changes in slope of the variation in frequency with time during a high accuracy calibration mode, prior to placing the VCO into real time operation. During the calibration mode the sweep rate of the VCO is slowed down as the operational frequency range of interest is divided into a prescribed number of subfrequency segments or windows. During each window, an input control code, obtained from a random access memory (RAM) and representative of the intended slope of the VCO frequency sweep (for that window of interest), is applied to a digital-to-analog converter (DAC) whose output is integrated and applied to the voltage control input of the VCO.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: February 12, 1985
    Assignee: Harris Corporation
    Inventors: David W. Thomson, Donald E. Trimble
  • Patent number: 4486717
    Abstract: A phase controlled oscillator comprises a first sweeping oscillator producing an output voltage controlled by a control input signal and a first sweeping signal within a limited output voltage amplitude, a second sweeping oscillator which produces a second sweeping signal having an amplitude smaller than that of the first sweeping signal supplied to a phase locked loop, the phase relation of input and output signals of the second sweeping oscillator being selected such that it stops oscillation when the loop is in a locked state, and a control circuit adapted to hold the output voltage of the first sweeping oscillator.
    Type: Grant
    Filed: January 6, 1983
    Date of Patent: December 4, 1984
    Assignee: Nippon Electric Co., Ltd.
    Inventor: Toyosaka Yamasaki
  • Patent number: 4482872
    Abstract: A swept frequency oscillator is capable of providing an output signal whose frequency can be swept over a very wide range at a rate which is not dictated by the period of the lowest frequency in the range. The signal detector monitors the output level of the oscillator so as to generate a control signal to remove variations in the output power level. At frequencies below a particular value, the time constant of the detector is modified progressively so as to be inversely proportional to the frequency being generated. Thus at low frequencies in the swept range, the time constant of the detector is increased.
    Type: Grant
    Filed: December 7, 1981
    Date of Patent: November 13, 1984
    Assignee: Marconi Instruments Limited
    Inventor: John D. Middleton
  • Patent number: 4480232
    Abstract: The average frequency and sweep rate of a chirped oscillator are automatically digitally controlled for correction of long term drift. During each of successive swept-frequency chirps, the swept frequency output of a voltage-controlled oscillator is counted and the overflow time of the counter is utilized to control the average frequency. A second counter counts the chirp frequency in a first direction during a first preset period at the beginning of each chirp and counts the chirp frequency in a second and opposite direction during an identical preset period later in the chirp, to provide an underflow transition related to the slope of the chirped frequency signal. Digital circuitry for synthesis of the chirped oscillator frequency ramp signal, and for correction of the average frequency and slope thereof responsive to the first and second counter transitions, is utilized.
    Type: Grant
    Filed: March 3, 1983
    Date of Patent: October 30, 1984
    Assignee: General Electric Company
    Inventors: Lewin T. Baker, Eugene J. Orlowski, Jr.
  • Patent number: 4470025
    Abstract: The starting frequency and sweep rate of a chirped frequency-shift-keyed oscillator are automatically controlled for correction of long-term drift. The substantially linear swept frequency output of the oscillator, during each of a successive multiplicity of swept frequency chirps, is counted and the count converted to an error signal utilized to control an appropriate potential in the oscillator circuit. The initial frequency is monitored, where the swept frequency range is small compared to the initial frequency, by counting the number of cyles during a chirp period in obtaining a first error signal from the total cycle count. The frequency-chirp ramp rate is monitored by counting the number of cycles during an initial portion, e.g.
    Type: Grant
    Filed: December 17, 1981
    Date of Patent: September 4, 1984
    Assignee: General Electric Company
    Inventor: Lewin T. Baker
  • Patent number: 4468638
    Abstract: A linear sweep frequency modulator for a varactor tuned transistor microwave oscillator used in an FM/CW radio altimeter where the oscillator-frequency v. varactor bias characteristic is non-linear. A linear triangular wave is converted by means of a function generator to the non-linear wave required for varactor bias to cause linear frequency modulation of the oscillator. Linearity of modulation is tested by measuring variations in the period of a calibration signal derived from a delay line. Variations in the period of the calibration signal are measured by determining the difference between the average and the instantaneous calibration period and sampling the difference during each cycle of the triangular wave, once during the upswing thereof when the oscillator is at low frequency and once during the down swing thereof when the oscillator is at high frequency and separately integrating the up swing and down swing samples.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: August 28, 1984
    Assignee: The Bendix Corporation
    Inventor: Constantinos S. Kyriakos
  • Patent number: 4419735
    Abstract: An improved driving signal source for an electrical analog of a reciprocating compressor generates a variable frequency sinusoidal output. The ratio between the electrical frequency used by the analog and the mechanical frequency of the modeled compressor is controlled by a ratio set switch. Upper and lower limits of the mechanical speed are operator determined, and the electrical output frequency is varied between the corresponding upper and lower electrical analog frequencies. The instantaneous output frequency of the improved source is displayed in terms of mechanical compressor speed. The ratio of electrical to mechanical frequency can be changed independently of the upper and lower mechanical speed settings.
    Type: Grant
    Filed: March 23, 1981
    Date of Patent: December 6, 1983
    Assignee: Southern Gas Association
    Inventor: Morton E. Brown
  • Patent number: 4417218
    Abstract: A circuit for linearizing the oscillator sweep output frequency signal of a oltage controlled oscillator is disclosed. The voltage controlled oscillator is driven by the output of an op amp, which amplifies and filters the output of a D/A converter. The D/A converter responds to preselected 8-bit words, stored in an EPROM, so as to produce a desired output frequency at each memory address. The addresses, in turn, are provided by a combination of gates, counters, input signals and a clock.
    Type: Grant
    Filed: June 19, 1981
    Date of Patent: November 22, 1983
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Herbert Berke
  • Patent number: 4398275
    Abstract: A device for producing a varying frequency sine wave synthesized so that frequency is swept linearly with time for use in a continuous transmission FM sonar. A crystal clock, divider and a 16 bit digital output sweep counter produce 2.sup.16 counts for each sweep period T.sub.s. The 2.sup.16 counts are applied to a 16 bit digital to analog converter to provide a highly linear voltage ramp (the smoothed result of 2.sup.16 steps). The ramp is converted to a proportional frequency which is applied to a 5 bit digital counter to access a read only memory programmed to provide a digital output representing points along a sine wave. The memory output is applied to a digital to analog converter to produce a voltage output that is a 32 stepped approximation of a sinewave at a frequency which increases betweeen f.sub.1 and f.sub.2 with the linearity of the ramp voltage. A filter smoothes the output.
    Type: Grant
    Filed: October 2, 1981
    Date of Patent: August 9, 1983
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: William J. Zehner
  • Patent number: 4389638
    Abstract: A yelping alarm signal generator has a current controlled audio oscillator with a feedback loop around it that produces a control current that is a direct function of the oscillation frequency so that only one capacitor external to the integrated circuits is required.
    Type: Grant
    Filed: September 30, 1981
    Date of Patent: June 21, 1983
    Assignee: Sprague Electric Company
    Inventor: Walter S. Gontowski, Jr.
  • Patent number: 4349789
    Abstract: The oscillation frequency of a variable frequency oscillator is swept by a sweep signal from a sweep signal generator and the oscillation frequency is compared with a preset sweep start frequency for detecting coincidence therebetween. Upon detecting the coincidence, the sweep operation of the sweep signal generator is stopped and, at the same time, the oscillation frequency of the variable frequency oscillator is made by phase lock loop means to be phase-synchronized with a reference frequency. When the phase synchronization is established, an error signal in the phase synchronization is held and the loop of the phase lock loop means is cut off and then the error signal is applied to the sweep signal generator to re-start the frequency sweep of the variable freqency oscillator. When coincidence is detected between the oscillation frequency of the variable frequency oscillator and a preset sweep stop frequency, the sweep operation is stopped.
    Type: Grant
    Filed: October 1, 1980
    Date of Patent: September 14, 1982
    Assignee: Takeda Riken Kogyo Kabushikikaisha
    Inventor: Takenori Kurihara
  • Patent number: 4346352
    Abstract: A sweep control circuit and method for maintaining a constant swept frequency range of a voltage-controlled oscillator when switching between linear and non-linear sweeping functions is provided. The sweep control circuit includes a linear amplifier and an antilogarithmic amplifier, each of which has an output voltage window that is matched to the linear dynamic range of the CVO. Independently selected start and stop voltages are adjustable over the entire linear range of the VCO to set the lower and upper frequency limits as desired for either a linear or a logarithmic sweep. Log converters are utilized to map the linear start and stop voltages to logarithmic counterparts so that the VCO frequency does not shift when switching from one function to the other. This permits a single start frequency control and a single stop frequency control to be employed. A ramp voltage, which is appropriately scaled for both the linear and logarithmic functions, is applied to sweep the VCO.
    Type: Grant
    Filed: September 30, 1980
    Date of Patent: August 24, 1982
    Assignee: Tektronix, Inc.
    Inventor: Robert E. Baetke