Field-effect Transistor Active Element Patents (Class 331/117FE)
  • Patent number: 5341111
    Abstract: A microwave oscillator circuit is provided for decreasing the number of passive elements such as inductance, etc. in microwave oscillators and frequency doublers. A microwave oscillator circuit is connected to a resonator circuit generating a signal at a frequency f, and produces at its output a signal of frequency nf, and comprises a first field effect transistor having a gate connected to the resonator circuit, a second field effect transistor whose source/drain path is connected in series with the source/drain path of the first field effect transistor and a connecting circuit for coupling either the gate or source of the first field effect transistor to the gate of the second field effect transistor. A signal of frequency nf is output at a node corresponding to a connection point between the source of the first field effect transistor and the drain of the second field effect transistor.
    Type: Grant
    Filed: September 16, 1992
    Date of Patent: August 23, 1994
    Assignee: NEC Corporation
    Inventors: Tatsuya Miya, Kazuyoshi Uemura, Sadayoshi Yoshida
  • Patent number: 5327106
    Abstract: An apparatus suitable for use as a local oscillator is disclosed, which includes (a) a tank circuit operatively associated with an FET to generate a fundamental frequency oscillating signal at an output of the FET and (b) a bi-directional clamp circuit coupled at a junction between the tank circuit and a gate of the FET to limit a swing of the gate of the FET, preventing the gate of the FET from entering either a saturation region or a cut-off region. The bi-directional clamp includes a first diode coupled to allow positive current to flow to the junction and a second diode coupled to allow positive current to flow away from the junction. The oscillator produces an output with a reduced level of radiation-prone harmonics.
    Type: Grant
    Filed: February 1, 1993
    Date of Patent: July 5, 1994
    Assignee: Delco Electronics Corp.
    Inventor: Stuart B. Sanders
  • Patent number: 5319802
    Abstract: In order to increase the sensitivity and range of a system for the exchange of data by microwaves between a fixed station, or reader, and a mobile station, or badge, the modem of the badge includes an oscillator. A single transistor works, under a first bias, as a detector of the wave transmitted by the reader and demodulates this wave, and then, under a second bias, it works as an oscillator and modulates the response transmitted by the badge. Applications to the exchange of data at a distance.
    Type: Grant
    Filed: November 15, 1991
    Date of Patent: June 7, 1994
    Assignee: Thomson Composants Microondes
    Inventors: Marc Camiade, Veronique Serru, Dominique Geffroy
  • Patent number: 5309119
    Abstract: An improved oscillating circuit for use in microwave frequency bands has reduced power loss and is made smaller in vertical size. The local oscillating circuit includes an MMIC oscillator which comprises a FET, and a resonator connected thereto so as to stabilize the oscillating frequency of the oscillator. The resonator is ring-shaped and arranged as close as several .mu.m to several tens of .mu.m to a predetermined position of a micro strip line forming a feedback loop connected to the FET forming the oscillator. Moreover, the resonator is a thin film formed by depositing a high-temperature superconducting material. As exemplary embodiments, YBCO, niobium and the like, can be used as high-temperature superconducting materials. Furthermore, a portion of the micro strip line, closest to the resonator, is concentrically disposed therewith to form a circular arc portion whose central angle is set at 90 degrees.
    Type: Grant
    Filed: July 14, 1992
    Date of Patent: May 3, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Nobuo Shiga
  • Patent number: 5291153
    Abstract: An oscillating circuit includes a substrate, a FET formed on the substrate, a series feedback capacitor connected to the source of the FET, a microstrip line formed on the substrate and connected to the gate of the FET, and a dielectric resonator which is electromagnetically coupled to the microstrip line. The dielectric resonator is located near the microstrip line.
    Type: Grant
    Filed: April 21, 1992
    Date of Patent: March 1, 1994
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Nobuo Shiga
  • Patent number: 5289139
    Abstract: A push-push microwave oscillator has two branch oscillators fabricated of a transistor and transmission line elements extending from terminals of the transistor, and a resonator which is fabricated of an annulus of superconductor material and serves to phase lock oscillations of the two branch oscillators. The superconductor material is a composite of a rare earth element and copper oxide such as yttrium-barium-copper oxide. A first transmission line in each of the branch oscillators extends past the resonator with a spacing to provide for electromagnetic coupling between the branch oscillator and the resonator. A second transmission line in each of the branch oscillators has a length equal to approximately one-quarter wavelength of the oscillation frequency to tune the branch oscillator to a common oscillation frequency.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: February 22, 1994
    Assignee: Space Systems/Loral
    Inventors: Slawomir J. Fiedziuszko, John A. Curtis
  • Patent number: 5248948
    Abstract: The oscillating apparatus according to this invention includes a pulse doped FET 1, and a series feedback capacitor 2 connected to the source of the pulse doped FET 1. The pulse doped FET is a FET formed on a pulse doped epitaxial layer including a channel layer 23 with a high carrier density, and a cap layer 24 with a low carrier density formed on the channel layer 23. The series feedback capacitor 2 is a variable capacitor whose capacitance value increases when a gate bias voltage of the pulse doped FET 1 is changed to increase a drain current of the pulse doped FET 1. Consequently it is possible to reduce phase noises by controlling only the gate bias with an oscillation frequency set at a required value. As a result, the merits of the MMIC can be sufficiently utilized without the necessity of externally adding a dielectric resonator.
    Type: Grant
    Filed: April 24, 1992
    Date of Patent: September 28, 1993
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Nobuo Shiga
  • Patent number: 5218325
    Abstract: A low noise oscillator for use in a radio which provides an output signal with high signal-to-noise ratio. The low noise oscillator includes a voltage controlled oscillator which produces an intermediate sinusoidal voltage signal in response to a DC tuning voltage. The voltage controlled oscillator includes a varactor and junction field effect transistor. The low noise oscillator also includes a buffer amplifier which receives the intermediate sinusoidal voltage signal from a tapped microstrip of the voltage controlled oscillator and produces a highly stable output signal proportional to the DC tuning voltage applied to the input of the low noise oscillator. The buffer amplifier employs a dual gate Gallium Arsenide field effect transistor.
    Type: Grant
    Filed: March 31, 1992
    Date of Patent: June 8, 1993
    Assignee: Motorola, Inc.
    Inventors: Eric Trelewicz, Michael N. Pickett, Robert H. Bickley
  • Patent number: 5191302
    Abstract: A self-excited solid-state oscillator for supplying a high-power RF inductive load. The oscillator includes at least one MOSFET transistor connected in a self-excited oscillator configuration, an output tuned circuit including an inductive load and a tank circuit connected to the load, the tank circuit having a resonant frequency determined at least in part by the inductance of the load, an RF feedback transformer coupling the tank circuit to the gate of the MOSFET for providing a switching signal to the MOSFET for causing the MOSFET to alternate between the on state and the off state at a frequency equal to the resonant frequency of the tank circuit, and a bias circuit for superimposing a forward bias voltage on the switching signal.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: March 2, 1993
    Assignee: Lepel Corporation
    Inventor: Melvin Rossnick
  • Patent number: 5180996
    Abstract: This invention relates to a high-frequency oscillator constituted by a signal generator for generating a high-frequency signal and a signal output circuit for outputting the generated high-frequency signal. The signal output circuit comprises a capacitor having one terminal to which the high-frequency signal output from the signal generator is applied, and a microstrip line having one terminal, which is connected to the other terminal of the capacitor, and the other terminal set at a reference potential. This signal output circuit can be miniaturized compared with those constituted only by microstrip lines such as conventional signal output circuits. By properly setting the capacitance of the capacitor and the size of the microstrip line, a filter function can also be imparted to the circuit.
    Type: Grant
    Filed: November 15, 1991
    Date of Patent: January 19, 1993
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Nobuo Shiga
  • Patent number: 5175513
    Abstract: A cascode amplifier having a 180.degree. phase characteristic is connected with in-phase feedback circuits having a 0.degree. phase characteristics. When viewed from an output side of the cascode amplifier, these circuits operate as inductive circuits having negative resistance. Thus, connecting a capacitor to the output of the cascode amplifier causes formation of a parallel resonance circuit, so that an oscillating operation is carried out. Since an inductor, i.e., inductive circuit can be structured without use of a transmission line, an occupied region necessary for formation of a microwave oscillation circuit is reduced.
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: December 29, 1992
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Shinji Hara
  • Patent number: 5164686
    Abstract: This invention is a high-frequency oscillator including a MESFET, wherein a GaAs MESFET, in which the doping profile of an active layer has a pulse-doped structure, is used as the MESFET. Since the GaAs MESFET is formed to have the pulse-doped structure, the change in transconductance with respect to the change in gate resistance remains constant at gate voltages within a predetermined range. When the gate voltage is set to be a voltage within this predetermined range, a capacitance change with respect to a gate voltage across a gate and a source is reduced. FM noise proportional to the magnitude of this capacitance change is reduced. Accurate information transmission is not interfered with unlike in conventional arrangements.
    Type: Grant
    Filed: November 15, 1991
    Date of Patent: November 17, 1992
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Nobuo Shiga
  • Patent number: 5157356
    Abstract: A microwave voltage controlled oscillator (12) and isolation amplifiers (14, 16) are formed as a monolithic circuit on a single GaAs substrate. Only a single external inductor (34) is required to set the oscillation frequency. Optionally, an external resonator (38) may be used instead of an inductor. Off-chip active bias control (LIMin, 18) is provided for convenient frequency tuning.
    Type: Grant
    Filed: May 3, 1991
    Date of Patent: October 20, 1992
    Assignee: Hughes Aircraft Company
    Inventor: Scott W. Wedge
  • Patent number: 5157357
    Abstract: A monolithic microwave IC oscillator includes a feedback amplifier having a field effect transistor and a varactor diode. The varactor diode has a junction capacitance that varies according to the bias voltage applied to said diode and capacitively couples the amplifier to an external load. Any variation of the capacitance of the load-coupling capacitor caused by design errors or by variations in the manufacturing process can be easily corrected when the device is used. As a consequence, the oscillator can always be operated with good oscillaitng characteristics without hindering integration of individual components and without increasing costs.
    Type: Grant
    Filed: July 25, 1991
    Date of Patent: October 20, 1992
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takayuki Katoh
  • Patent number: 5130675
    Abstract: A voltage-controlled oscillator according to the present invention comprises: a transistor, where the drain electrode is grounded, the gate electrode is connected to a resonator whose resonant frequency is adjustable according to a voltage applied to a voltage-dependent capacitance diode electromagnetically coupled with the resonator, an output signal is output from the source electrode; a resistor connected in gate bias circuit or source voltage supply circuit for detecting a low-frequency noise component generated in the transistor, where the detected low-frequency noise component is amplified and fed back to the voltage-dependent capacitance diode so as to cancel a phase-noise component generated in the voltage-controlled oscillator. The above-described voltage-controlled oscillator may be further provided with a reference crystal oscillator to which the voltage-controlled oscillator is phase-locked.
    Type: Grant
    Filed: September 4, 1991
    Date of Patent: July 14, 1992
    Assignee: Fujitsu Limited
    Inventor: Hideo Sugawara
  • Patent number: 5122765
    Abstract: A microwave circuit intended for either direct modulation or direct demodulation of a microwave link communications signal is characterized in that a local oscillator (8) is incorporated in the circuit. The local oscillator supplies two signals that are in phase opposition at 180 degrees. Each signal is sent to a phase shifter. The first phase shifter (9) supplies two signals that are in quadrature, at 0 and 90 degrees. The second phase shifter supplies two signals in quadrature at 180 and 270 degrees. The 0 and 180 degree signals are sent to a first mixer (2), while the 90 and 270 degree signals are sent to a second mixer (3). In the case of a modulator, the first and second mixers receive, respectively, in-phase and quadrature signals, and the outputs of the mixers are combined to form a modulated signal. In the case of a demodulator, a modulated signal is applied through a .div.2 divider to inputs of the two mixers, and in-phase and quadrature signals are obtained at respective mixer outputs.
    Type: Grant
    Filed: December 12, 1989
    Date of Patent: June 16, 1992
    Assignee: Thomson Composants Microondes
    Inventor: Gerard Pataut
  • Patent number: 5117205
    Abstract: An electrically controllable oscillator circuit (30) comprises two balanced transconductance circuits (G1, G2), each including transistor pairs arranged as inverters (Inv14) and as resistors (Inv5-6). The oscillation frequency (f) and the quality factor (Q) of the oscillator circuit (30) are controlled by means of a single control signal provided by a combined control circuit (Inv7, Dif, IM1, IM2). The current mirror circuit (IM1, IM2) and a differential pair (Dif) derived the control signal for adjusting the quality factor (Q) from a resistor-connected further transistor pair (Inv7) connected to the control signal for adjusting the frequency (f). The quality factor of an electrically controllable filter arangement including similar transconductance circuits (G-3-9) is adjusted by means of the control signal generated by the control circuit via a buffer circuit (B) and a low-pass circuit (C3).
    Type: Grant
    Filed: April 12, 1991
    Date of Patent: May 26, 1992
    Assignee: U.S. Philips Corporation
    Inventor: Bram Nauta
  • Patent number: 5115210
    Abstract: An ambient condition sensor is embodied in an oscillator which generates an output signal having a frequency which is proportional to the ambient condition of the environment in which it is located. The oscillator includes a ring resonator consisting of a metallic ring located in the output plane of a grounded source gallium arsenide MESFET type transistor oscillator formed on a temperature sensitive dielectric substrate. The circumference of the ring is directly related to the ring resonator's resonant frequency. More particularly, the circumference of the ring is a multiple of the wavelength of the oscillator's output signal. Such a device permits unmanned, remote and inexpensive temperature sensing in places generally unsuited for operator presence.
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: May 19, 1992
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Michael Cummings, Roland Cadotte, Jr., Adam Rachlin
  • Patent number: 5087895
    Abstract: A miniature microstrip/cavity oscillator which is mechanically tunable over a wide range of microwave frequencies and maintains high frequency stability over changes in temperature. The oscillator consists of a RF (resonant frequency) determining element, a microstrip circuit board means, and a capacitive coupling probe coupling the microstrip circuit board means to the RF determining element. The RF determining element is constructed of various materials with different coefficients of linear expansion to eliminate expansion and contraction effects due to temperature changes.
    Type: Grant
    Filed: February 2, 1988
    Date of Patent: February 11, 1992
    Assignee: Motorola, Inc.
    Inventor: Bernard E. Sigmon
  • Patent number: 5087896
    Abstract: A coplanar waveguide based microwave monolithic integrated circuit (MMIC) oscillator chip (14) having an active oscillator element (16) and a resonant capacitor (18) formed thereon is flip-chip mounted on a dielectric substrate (12). A resonant inductor (22) is formed on the substrate (12) and interconnected with the resonant capacitor (18) to form a high Q-factor resonant circuit for the oscillator (10). The resonant inductor (22) includes a shorted coplanar waveguide section (24) consisting of first and second ground strips (24b,24c), and a conductor strip (24a) extending between the first and second ground strips (24b,24c) in parallel relation thereto and being separated therefrom by first and second spaces (26a,26b) respectively. A shorting strip (24d) electrically interconnects adjacent ends of the conductor strip (24a) and first and second ground strips (24b,24c) respectively.
    Type: Grant
    Filed: January 16, 1991
    Date of Patent: February 11, 1992
    Assignees: Hughes Aircraft Company, Delco Electronics Corporation
    Inventors: Cheng P. Wen, Gregory S. Mendolia, Mario Siracusa, Joseph J. Maieron, William D. Higdon
  • Patent number: 5043680
    Abstract: A magnetron is powered via an output transformer TR whose primary winding (a) is connected in series with a resonant converter oscillator circuit comprising an inductor (L) and a capacitor (C3) and switching transistors (T.sub.1, T.sub.2) which are connected to positive and negative power supply terminals and are switched by respective current transformers (CT1, CT2). The switching points of the switching transistors are varied so as to vary the output of the circuit by varying the positive and negative flux excursions in the cores of the transformers (CT1, CT2) such that the net flux excursions are sufficient to saturate the transformers and switch off the switching transistors at a predetermined point in each half cycle. The relative positive and negative flux excursions in the transformer cores are controlled by providing additional windings (g) which are connected to a control circuit whcih rectifies the output of these windings and controls the rectified DC voltage appearing across them.
    Type: Grant
    Filed: March 29, 1990
    Date of Patent: August 27, 1991
    Assignee: Aktiebolaget Electrolux
    Inventor: David Gurwicz
  • Patent number: 5039958
    Abstract: An integrated semiconductor device, including an insulated-gate field effect transistor biased to a constant level in order to obtain for the transistor an N-shaped drain-source current characteristic as a function of the drain-source voltage so that it presents a negative differential conductance zone, characterized in that it comprises means for applying, between the drain and the source of the field effect transistor, a voltage whose value is in the range of values the drain-source voltage corresponding to the negative conductance zone.
    Type: Grant
    Filed: January 19, 1990
    Date of Patent: August 13, 1991
    Assignee: U.S. Philips Corporation
    Inventors: Etienne Delhaye, Michel Wolny, Thierry Aguila, Ramesh Pyndiah
  • Patent number: 4990865
    Abstract: A microwave oscillator having at least one transistor (1), which may be bipolar or otherwise. A tunable reactive circuit (13, 15, 16) suitable for adjusting the transistor's zone of potential instability is inserted in the emitter circuit of the transistor (1) (or in the source circuit of an FET). The reactive circuit comprises a series length of transmission line (13) and a parallel capacitance (15, 16) constituted, at least in part, by a conducting slab (15) of adjustable size.
    Type: Grant
    Filed: March 14, 1990
    Date of Patent: February 5, 1991
    Assignee: Alcatel N.V.
    Inventor: Michel Martheli
  • Patent number: 4988959
    Abstract: A broadband YIG-tuned oscillator is disclosed that has both series and parallel feedback provided by a YIG sphere. The oscillator includes a transistor capable of driving a load coupled to a first port of the transistor, a reactive feedback element coupled to a second port of the transistor, a YIG resonator, and coupling means for coupling the YIG resonator to both a third port of the transistor and to the first port of the transistor.
    Type: Grant
    Filed: October 31, 1989
    Date of Patent: January 29, 1991
    Assignee: Avantek, Inc.
    Inventors: Amarpal S. Khanna, Derek Davis
  • Patent number: 4987389
    Abstract: Three series connected inverters (38, 40, 42) are attached to a tank circuit (18) which includes an inductance (12, 14) and a capacitance (16, 17). Negative (38) biases the inverters at the midpoint between the bistable low and high logic level states. Positive feedback from the second inverter (40) to the tank circuit induces oscillation in the tank circuit. The negative feedback is decoupled at the resonant frequency and the energy delivered to the tank circuit from the positive feedback maintains a low level oscillation in the tank circuit. Negative feedback around the three inverter digital circuit prevents lockup in the event of power loss or momentary short.
    Type: Grant
    Filed: April 2, 1990
    Date of Patent: January 22, 1991
    Assignee: Borg-Warner Automotive, Inc.
    Inventors: Amnon Brosh, Wolf S. Landmann
  • Patent number: 4985642
    Abstract: A high-frequency circuit includes a field-effect transistor having a gate electrode for receiving a high-frequency input signal, a source electrode and a drain electrode. Substantial improvements in both maximum gain and high-frequency performance are achieved by providing an input or output terminal at one end of each electrode, and terminating at least one of the electrodes with an appropriate impedance at its second end.
    Type: Grant
    Filed: December 14, 1988
    Date of Patent: January 15, 1991
    Assignee: U.S. Philips Corp.
    Inventor: Patrice Gamand
  • Patent number: 4949053
    Abstract: An oscillator including an active gain device and feedback between the output of the the device and its input for sustaining oscillations that incorporates a power splitter between the output of the device, the output of the oscillator and a feedback path for isolating the feedback path from the output of the oscillator for improving power and frequency pushing.
    Type: Grant
    Filed: September 1, 1989
    Date of Patent: August 14, 1990
    Inventor: Richard C. Havens
  • Patent number: 4906946
    Abstract: A feedback type microwave oscillator using a three-terminal active element employs both series feedback and parallel feedback and capacitance in its output circuit, thereby increasing the small signal negative resistance, and the output power and its resistance to impedance fluctuations of a load attached thereto.
    Type: Grant
    Filed: September 23, 1988
    Date of Patent: March 6, 1990
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tsuyoshi Mekata, Hiroshi Saka, Toshihide Tanaka
  • Patent number: 4873498
    Abstract: A reflection oscillator is provided which employs an active device operated in its roll-off region and two resonant circuits. For an oscillator employing a bipolar transistor, the emitter is connected to a series resonant capacitor-crystal network and the base is connected to an L-C tank circuit with the transistor being operated in the roll-off region of its gain versus frequency curve. This will provide a very high frequency of operation with a relatively inexpensive, low frequency, active device. These oscillators are easily tuned, stable, and require little d.c. power.
    Type: Grant
    Filed: December 30, 1988
    Date of Patent: October 10, 1989
    Assignee: The United States of America as represented by the Administrator, National Aeronautics and Space Administration
    Inventor: Leonard L. Kleinberg
  • Patent number: 4868526
    Abstract: An ultrahigh-frequency oscillator. To double the frequency of an oscillator having a single field-effect transistor (10), whose fundamental frequency is adjusted by an impedance of gate (13) and an impedance of source (15), a filter (16+17) is mounted between the drain of transistor (10) and the ground. This filter, formed by a self-induction coil (16) in series with a varactor (17) is adjusted to the fundamental frequency: it assures the rejection, and favors the generation of the second harmonic, at double frequency. Application to ultrahigh-frequency sources.
    Type: Grant
    Filed: December 16, 1988
    Date of Patent: September 19, 1989
    Assignee: Thomson Hybrides et Microondes
    Inventors: Marc Camiade, Alain Bert, Pierre Savary
  • Patent number: 4849716
    Abstract: An optical injection locking oscillator is comtemplated having a tuning device. The tuning device generates a DC voltage proportional to the resonant frequency of a modulated light used to injection lock the free running oscillator. The DC voltage is applied to a varactor capacitor within the oscillator to bring the frequency of oscillation within a close proximity to the modulating frequency of the light. This facilitates injection locking, whereas frequencies of oscillation outside a certain locking range will not facilitate injection locking. The modulated light then locks the oscillator into a desired resonant frequency. A second embodiment contemplates using a YIG oscillator regulated by a DC current generated within the tuning device.
    Type: Grant
    Filed: August 15, 1988
    Date of Patent: July 18, 1989
    Assignee: Motorola, Inc.
    Inventors: John M. Golio, David A. Warren
  • Patent number: 4841353
    Abstract: A transistor device for a microwave oscillating element having an FET transistor chip and a package encapsulating the chip therein. In order to avoid any affection of the external circuit to the input impedance of the transistor device and to make the phase rotation low at a frequency band higher than the X band, a conductor element is provided within the package to connect the drain electrode of the chip and a corresponding terminal of the package. The conductor element has an inductance to provide a sufficient high impedance at the intended frequency band. The conductor element is supported on an insulator plate fixedly mounted within the package.
    Type: Grant
    Filed: November 24, 1987
    Date of Patent: June 20, 1989
    Assignee: NEC Corporation
    Inventors: Kenzo Wada, Eiji Nagata
  • Patent number: 4812785
    Abstract: A gyrator circuit usable in a resonant filter circuit comprises a first and a second transconductance amplifier circuit, A and B, respectively, having opposite conductances, which amplifiers are arranged in parallel between a first terminal a and a second terminal b and comprise a first capacitance C.sub.1 arranged between said first terminal a and an earth terminal m, which gyrator circuit simulates an inductance L.sub.g arranged between said second terminal b and said earth terminal m and comprises means for controlling the quality factor Q of said inductance, characterized in that the first transconductance amplifier circuit A comprises two series-connected inverting amplifier stages P.sub.1 and P.sub.2, in that the second transconductance amplifier circuit B comprises an inverting amplifier stage P.sub.3, and in that the means for controlling the quality factor Q comprise a first means P.sub.5 for influencing the output conductance q.sub.2 of the gyrator and a second means P.sub.
    Type: Grant
    Filed: July 24, 1987
    Date of Patent: March 14, 1989
    Assignee: U.S. Philips Corporation
    Inventor: Vlad Pauker
  • Patent number: 4806884
    Abstract: A high frequency generator for sinusoidal output power includes an LC-parallel resonance circuit as an output circuit. A plurality of HF-modules of small output are coupled to the output circuit. Each HF-module consists of a controlled switch S1.1, S1.2, which is wired with a .lambda./4-line LL1, LL2. The coupling-in of the sinusoidal high frequency power occurring at the outputs of the .lambda./4-lines LL1, LL2 onto the output circuit occurs through coupling condensers CK1, CK2 and primary coils L1, L2. The voltage supply U.sub.B is provided by a timed circuit network portion 1, to which the line voltage 2 and a desired value 3 for the modulation of the HF-output power are fed. The operating voltage UB is fed to each HF-module through its own switch S2.1, S2.2, a filter condenser CL1, C12 and a .lambda./4-line LL7, LL8. Short-circuiting switches SK1, SK2 in parallel with each control switch S1.1, S1.2 see to it, in case of a switch malfunction, that the output circuit is only minimally detuned.
    Type: Grant
    Filed: March 12, 1987
    Date of Patent: February 21, 1989
    Assignee: Elan Elektronische Anlagen GmbH
    Inventor: Winfried P. Rutt
  • Patent number: 4797634
    Abstract: A controlled crystal oscillator of a stereo decoder of a television receiver using CMOS technology includes first, second and third differential emplifiers that produce corresponding first, second and third pairs of anti-phase output signals. The first and second differential amplifiers have variable gains that vary in opposing manners in accordance with a frequency control signal. The oscillatory signal of a crystal is coupled to corresponding input terminals of the three differential amplifiers such that the phase of the signal that is developed at the input terminal of the third differential amplifier is phase-shifted by approximately 90.degree. relative to those developed at the input terminals of the other two amplifiers. The three pairs of output signals are combined to form a single-ended oscillatory signal that is coupled back to the crystal to complete a regulative feedback path. The frequency of oscillation is determined in accordance with the frequency control signal.
    Type: Grant
    Filed: August 31, 1987
    Date of Patent: January 10, 1989
    Assignee: RCA Licensing Corporation
    Inventor: Paul D. Filliman
  • Patent number: 4786903
    Abstract: A radio frequency transponder is provided that combines high signal sensitivity in the receive mode and variable frequency capability in the transmit mode in a low component and power efficient design. A single tuned amplifier acts as the externally quenched oscillator of a superregenerative receiver when the transponder is operated in the receive mode, and as the carrier frequency generator when the transponder is operated in the transmit mode.
    Type: Grant
    Filed: June 1, 1987
    Date of Patent: November 22, 1988
    Assignee: E. F. Johnson Company
    Inventors: Mervin L. Grindahl, George Rosar, Mark Kodet
  • Patent number: 4785264
    Abstract: A dual FET oscillator includes a first J-FET and a second J-FET connected to it as a source follower. A turned circuit is connected to the gate of the first J-FET and to the second J-FET. Bias voltage is supplied to both J-FET's. Schottky diodes are connected to both J-FET's to limit gate-source voltage.
    Type: Grant
    Filed: May 28, 1987
    Date of Patent: November 15, 1988
    Assignee: Motorola, Inc.
    Inventors: Robert S. Kaltenecker, Robert E. Stengel, Ralph T. Enderby, James S. Irwin
  • Patent number: 4785263
    Abstract: A Ga As FET oscillator includes an FET having gate-drain and source connections. A tuned circuit is connected to the FET gate. Bias voltage is supplied to the FET. A parallel-connected resistor and capacitor is connected to the FET source. A Schottky diode is connected across the FET gate-source junction and the parallel connected resistor and capacitor, with its anode connected to the FET gate and its cathode connected to the resistor and capacitor. The Schottky diode limits the positive voltage across the gate-source junction of the Ga As FET to prevent gate-source current flow.
    Type: Grant
    Filed: May 28, 1987
    Date of Patent: November 15, 1988
    Assignee: Motorola, Inc.
    Inventors: Robert S. Kaltenecker, Robert E. Stengel, Ralph T. Enderby, James S. Irwin
  • Patent number: 4783638
    Abstract: The invention pertains to a doubling oscillator with low noise in the vicinity of the carrier frequency. The doubling oscillator of the invention is of the "push-push" type comprising two parallel-mounted transistors. The gates of these two transistors have a common oscillating circuit comprising two microstrip lines, two resistors and a common dielectric resonator positioned between the two microstrip lines. To reduce the low-frequency noise in the vicinity of the carrier near the load, the non-correlated low frequency noise sources of the transistors are either placed in series by means of a choke and two capacitances mounted at the ends of the microstrips or loaded at an infinite impedance through two capacitances mounted at the ends of the microstrips. This oscillator has applications in ultra-high frequency systems, radars and telecommunications.
    Type: Grant
    Filed: June 10, 1987
    Date of Patent: November 8, 1988
    Assignee: Thomson-CSF
    Inventors: Marguise Mamodaly, Pascal Colin, Alain Bert, Juan Obregon
  • Patent number: 4783849
    Abstract: The RF stage and local oscillator stage of a tuner both include respective cascode connected dual gate field effect transistors as the amplifying device and similarly configured tuned circuits coupled to the first gate electrodes of the field effect transistors. The tracking characteristics of the tuner are enhanced due to the similar amplifier and tuned circuit configurations.
    Type: Grant
    Filed: November 26, 1986
    Date of Patent: November 8, 1988
    Assignee: RCA Licensing Corporation
    Inventor: Max W. Muterspaugh
  • Patent number: 4775845
    Abstract: The present invention provides an alternative circuit for microwave oscillators. The invention consists of an amplifier, signal divider, filter(s), and optional limiter. The feedback path is external to the amplifier, allowing direct access and control of the loop phase and loop gain. Control of the loop gain can be used for applications such as amplitude modulation of the oscillator's output or control of the oscillator's output power. Control of the loop phase can be used to frequency modulate the oscillator or to create a voltage-controlled oscillator. Dynamic control of the loop gain with a limiter enables one to maintain linear operation throughout the oscillator. Linear operation is often desirable to eliminate the 1/f noise contributions at the frequency of operation and to enable the use of small signal s-parameters in the design and analysis.
    Type: Grant
    Filed: April 24, 1987
    Date of Patent: October 4, 1988
    Inventor: Jody A. McCoy
  • Patent number: 4768079
    Abstract: A two-terminal field effect transistor device which is capable of operation as an oscillator including a field effect transistor connected in a two-terminal manner. The transistor has the usual drain source and gate electrodes and oscillating instability is provided by means of an inductance means of value so as to provide this circuit instability to enable circuit oscillations. The two-terminal arrangement is enabled by means of essentially interconnecting the gate and drain electrodes by way of said inductance means.
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: August 30, 1988
    Assignee: M/A Com, Inc.
    Inventors: Pramode Kandpal, Jean C. Collinet, Bernhard A. Ziegner, James A. Bowen
  • Patent number: 4757433
    Abstract: A power converter, particularly adapted for supplying high voltage power for a CRT, for converting an unregulated level of input power to a regulated level of output power is described. The power converter includes a self-excited sinusoidal power oscillator comprising a transformer which has a secondary winding that resonates at a resonating frequency in response to the input signal and a field effect transistor connected to operate as a Class C amplifier. The field effect transistor is connected so that both the drain and gate voltages can both be provided by the primary windings of the tranformer and oscillate at the resonant frequencies so that the positive peak gate voltage can be used to control the output of the power oscillator, which in turn controls the power output of the converter. The gate of the FET is connected to a control bus which in turn can be connected to controls for controlling the control signal in accordance with any one of a plurality of control conditions.
    Type: Grant
    Filed: January 7, 1987
    Date of Patent: July 12, 1988
    Assignee: Display Components, Inc.
    Inventor: William F. Santelmann, Jr.
  • Patent number: 4755772
    Abstract: A switchable microwave oscillator is disclosed that includes a quenching circuit for switching, attenuating, modulating, or otherwise controlling the output amplitude of frequency-stabilized, transistor-based, microwave-frequency oscillators. The quenching circuit includes a diode that is coupled to the transistor at the same port that reactive feedback is present, and includes diode biasing means for selectively applying a bias voltage to the diode. The quenching circuit selectively diverts some of the current flowing through the transistor of the oscillator to control the output thereof.
    Type: Grant
    Filed: June 5, 1987
    Date of Patent: July 5, 1988
    Assignee: Avantek, Inc.
    Inventor: Amarpal S. Khanna
  • Patent number: 4754236
    Abstract: A frequency-doubling voltage-controlled oscillator (VCO) for use in the microwave frequency range has two channels which operate in parallel. A transistor is mounted as an oscillating system in each channel and its energy is collected on the drain electrode. The two transistors are mounted with their output currents in opposite phase, thus reducing FM noise in the vicinity of the carrier. In accordance with the invention, phase opposition is obtained by means of a varactor connected between the gates of the two transistors. The varactor is decoupled in direct current by means of two capacitors. In order to increase the range of frequencies, two additional varactors can be mounted in like manner on the source circuits of the two transistors.
    Type: Grant
    Filed: April 15, 1987
    Date of Patent: June 28, 1988
    Assignee: Thomson-CSF
    Inventors: Narguise Mamodaly, Didier Kaminsky
  • Patent number: 4748383
    Abstract: A DC-AC converter for igniting and supplying a low-pressure discharge lamp, e.g. an electrodeless low-pressure gas discharge lamp. The converter has two input terminals (9, 10) for connection to a d.c. voltage source. The input terminals are connected to a series arrangement controlled semiconductor switching element (12), a first coil (14) and a parallel circuit having the discharge lamp 15 in one of its branches. The control electrode and a main electrode of the controlled semiconductor switching element are connected together by means of a secondary winding (21) of a transformer (17) having a primary winding (16) that forms a part of the parallel circuit. The converter includes a starter circuit comprising a resistor (28) connected between a main electrode and the control electrode of the semiconductor switching element and a capacitor (29) coupled between the control electrode and one end of the secondary winding (21) of the transformer.
    Type: Grant
    Filed: October 27, 1986
    Date of Patent: May 31, 1988
    Assignee: U. S. Philips Corporation
    Inventor: Henk Houkes
  • Patent number: 4743866
    Abstract: A local oscillator is arranged in a Colpitts type configuration in which an amplifying device such as a bipolar transistor or field effect transistor having a control electrode (base or gate electrode) is coupled to a first electrode (emitter or source electrode) defining the end of a conduction channel through an oscillation conditioning network conditioning the device to oscillate in a given range and also to a frequency determining network including a first varactor diode responsive to the tuning voltage and an inductance element coupled in series between the control electrode and signal ground, and in which the output is taken at a second electrode (collector or drain) defining the other end of the conduction channel. A range extending circuit including a second varactor diode responsive to the tuning voltage is coupled between the control electrode and signal ground for ensuring that the oscillator operates reliably at both ends of the tuning range.
    Type: Grant
    Filed: November 26, 1986
    Date of Patent: May 10, 1988
    Assignee: RCA Corporation
    Inventor: Max W. Muterspaugh
  • Patent number: 4736168
    Abstract: In a dielectric resonator controlled oscillator with frequency multiplication, a line (12) has an open end and another end connected to a gate electrode of an FET (11) with a dielectric resonator (13) electromagnetically coupled to the line at a location along a total length of the line. The total length is selected to make a combination of the line and the dielectric resonator have a substantially zero impedance for a higher harmonic frequency when seen from the gate electrode. More specifically, the total length is selected so as to be equal to about three quarters of a wavelength which a frequency multiplied oscillation, such as a frequency doubled oscillation, has in the line. The location is selected so as to optimize the oscillator for a fundamental oscillation of a fundamental frequency determined by the dielectric resonator.
    Type: Grant
    Filed: March 18, 1987
    Date of Patent: April 5, 1988
    Assignee: NEC Corporation
    Inventor: Eiji Nagata
  • Patent number: 4734658
    Abstract: An ultra low voltage energized oscillator for providing a stepped-up alternating current voltage is provided. This oscillator utilizes a field effect transistor with a high impedance network including a capacitor coupling a feedback signal from a secondary output winding to a primary input winding of a transformer.
    Type: Grant
    Filed: August 14, 1987
    Date of Patent: March 29, 1988
    Assignee: Honeywell Inc.
    Inventor: John E. Bohan, Jr.
  • Patent number: 4727339
    Abstract: An amplifier having a resonator coupled between input and output terminals thereof supplies a dot clock signal to a character generator in a television receiver. A feedback control circuit supplies DC bias to the resonator during blanking intervals that preceed lines of characters to be displayed to ensure a consistent starting phase for oscillations, removes the DC bias and supplies operating power to the amplifier during a portion of the active video period of each displayed line for sustaining the oscillations and automatically inhibits the supply of amplifier power at the end of each active line of characters to thereby provide three oscillator operating modes of PRIMED, RUNNING and OFF so as to minimize overall power consumption for the oscillator for each field of displayed characters.
    Type: Grant
    Filed: October 30, 1986
    Date of Patent: February 23, 1988
    Assignee: RCA Corporation
    Inventors: James H. Doty, II, Walter G. Gibson