Negative Resistance Amplifiers Patents (Class 330/61A)
  • Patent number: 5920231
    Abstract: There is provided a negative differential resistance amplifier comprising a negative differential resistance transistor having negative input conductance by utilizing resonant tunneling effect. The transistor is electrically connected to a signal source circuit in cascade, and the following relation is established in the negative differential resistance amplifier:0<gs-gi<Gwherein gs (gs>0) indicates a conductance measured when viewed from an interface between the negative differential resistance transistor and the signal source circuit to the signal source circuit, -gi (gi>0) indicates a conductance of the negative differential resistance transistor, and G (G<gs) indicates a predetermined conductance. The above mentioned negative differential resistance amplifier provides not only excellent signal unilaterality, but also higher gain, lower noise and wider band by setting certain matching conditions between the negative differential resistance transistor and the signal source circuit.
    Type: Grant
    Filed: August 11, 1997
    Date of Patent: July 6, 1999
    Assignee: NEC Corporation
    Inventor: Yuji Ando
  • Patent number: 4409557
    Abstract: An amplifier including an in phase feedback signal to therefore exhibit negative resistance is receptive of an input alternating signal which includes a frequency F. The output of the amplifier is coupled to a resonator adjusted to a center frequency F and having undesirable resistance which is offset by the negative resistance of the amplifier. The resonator includes an inductor and adjustable capacitor arranged either in series or in parallel with the amplifier to therefore change the value of F.
    Type: Grant
    Filed: April 23, 1981
    Date of Patent: October 11, 1983
    Assignee: RCA Corporation
    Inventor: Franco N. Sechi
  • Patent number: 4338582
    Abstract: An electronically adjustable capacitor (varactor), an active element such as a Field Effect Transistor arranged to exhibit negative resistance, and an inductor are arranged as a frequency tunable resonator suitable for use at microwave frequencies. The negative resistance of the active element may be adjusted to compensate for the resistance of the other resonator components such that the resonator exhibits very high Q and therefore high selectivity and low loss. The resonator may be used as a filter element in a tunable filter. Alternatively the negative resistance of the active element may be adjusted such that the resonator exhibits net negative resistance and may be incorporated in a tunable reflection type amplifier.
    Type: Grant
    Filed: August 27, 1979
    Date of Patent: July 6, 1982
    Assignee: RCA Corporation
    Inventor: Adolph Presser
  • Patent number: 4175257
    Abstract: A modular microwave power combiner having a plurality of identical microwave diode amplifier circuits grouped in sets within the body of a modular unit which are electrically coupled in parallel to a central cavity sized to be resonant at a single frequency to minimize mismoding thereby enhancing combiner efficiency. A number of waveguides are provided for coupling of the microwave diode in each amplifier circuit to the resonant cavity, and the waveguides are situated on one side of a PC board at the top of each modular unit. Since each of the modular units is essentially identical in physical size and shape, the overall power output of the power combiner can be increased by merely adding additional modular units. The individual modular units are sized to fit top-to-bottom such that the respective resonant cavities are spaced apart by one-half wavelength (.lambda./2) for the parallel electrical coupling of all of the resonating cavities.
    Type: Grant
    Filed: October 5, 1977
    Date of Patent: November 20, 1979
    Assignee: United Technologies Corporation
    Inventors: Peter W. Smith, Rudolph G. Mastrioanni
  • Patent number: 4090155
    Abstract: A transmission line is disclosed which comprises a conductive layer, a resistive semiconductor layer disposed on the conductive layer and a blocking electrode disposed on the resistive semiconductor layer. By applying a biasing voltage between the blocking electrode and the conductive layer, a depletion layer is produced in the resistive semiconductor layer, the depletion layer formed in the semiconductor layer being used as a medium for transmission of electromagnetic wave.
    Type: Grant
    Filed: March 22, 1976
    Date of Patent: May 16, 1978
    Assignee: Agency of Industrial Science & Technology
    Inventors: Hiroshi Tateno, Shoei Kataoka, Nobuo Hashizume, Yasuo Komamiya
  • Patent number: 4063186
    Abstract: A millimeter wave amplifier having broadband characteristics in which a G diode or other two terminal negative resistance device having an integral heat sink is center mounted in a reduced height waveguide. The heat sink is attached to a mechanism for selectively adjusting its penetration into the waveguide cavity. The introduction of the heat sink into the waveguide cavity creates a discontinuity to the propagation of energy which causes localized waveguide modes other than the dominant mode to exist. The adjustable position of the heat sink allows the reactance due to the introduction of these modes to be variable, proper adjustment resulting in the cancellation of the parasitic reactances inherent in the packaged negative resistance device.
    Type: Grant
    Filed: October 10, 1975
    Date of Patent: December 13, 1977
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: David Rubin
  • Patent number: 4050032
    Abstract: A microwave amplifier is disclosed using a nonreciprocal three port junction circulator. The amplifier uses a ferrite circulator having an input port, an output port and a third electrical port. A semiconductor device such as an IMPATT diode having negative resistance is located adjacent and electrically coupled to the third electrical port. The negative resistance of the IMPATT diode combines with the output response of the third electrical port of the circulator to provide power amplification of microwave signals received on the input port.
    Type: Grant
    Filed: January 2, 1976
    Date of Patent: September 20, 1977
    Assignee: Texas Instruments Incorporated
    Inventor: Hua Quen Tserng
  • Patent number: 4025872
    Abstract: A network characterized at a reference terminal pair by a negative resistance at a frequency near nf.sub.o, where n is an integer greater than one. The network comprises a circuit element characterized by a negative resistance at frequencies in the range f.sub.1 to f.sub.2 where f.sub.1 < f.sub.o < f.sub.2, a passive non-linear network and a filter network for coupling the negative resistance element to the passive non-linear network only at frequencies near f.sub.o and to the reference terminal pair only at frequencies near nf.sub.o. The negative resistance network may be configured with suitable components as a negative resistance amplifier and as an injection locked oscillator.
    Type: Grant
    Filed: August 1, 1975
    Date of Patent: May 24, 1977
    Inventor: Alfred I. Grayzel
  • Patent number: 4021750
    Abstract: A broad-band microwave amplifier including a semiconductor TRAPATT diode generating a microwave signal at its fundamental, second and third harmonic frequencies. Energy is extracted at the second harmonic frequency and a certain impedance loading is provided at the fundamental and third harmonic frequencies by an open-ended tapered microstrip idler circuit connected in parallel with the diode. The tapered idler circuit also provides a predetermined relatively small rate of change of impedance with respect to frequency changes to obtain a wide instantaneous bandwidth of the amplifier.
    Type: Grant
    Filed: December 24, 1975
    Date of Patent: May 3, 1977
    Assignee: RCA Corporation
    Inventors: Pang-Ting Ho, Arye Rosen
  • Patent number: 4009446
    Abstract: A Microwave reflection amplifier having improved gain, bandwidth and noise characteristics, uses two negative-resistance diodes, such as Gunn-effect diodes, connected in series across the terminals. The diodes are series resonated by inductance in their leads. The gain and bandwidth are higher than in amplifiers using a single diode. A shunt-resonant circuit is connected across one diode to improve the gain-bandwidth. A second shunt-resonant circuit may be connected across the terminals. At very high frequencies, the amplifier uses strip-line or microstrip circuitry and the shunt resonators are half-wavelength transmission lines.
    Type: Grant
    Filed: March 19, 1976
    Date of Patent: February 22, 1977
    Assignee: Varian Associates
    Inventors: Joseph G. De Koning, Robert E. Goldwasser, Robert J. Hamilton, Jr.
  • Patent number: 4005372
    Abstract: A frequency tunable microwave apparatus including a semiconductor TRAPATT diode generating a microwave signal at its fundamental, second and third harmonic frequencies. Energy is extracted at the second harmonic frequency and a certain impedance loading is provided at the fundamental frequency and third harmonic by a variable impedance hybrid idler circuit. The hybrid idler circuit comprises a distributed transmission line serially connected to a lumped variable capacitor. Variations in the capacitance of the variable capacitor tune the fundamental frequency without substantially varying the impedance loading conditions of the diode allowing energy to be extracted at the second harmonic frequency throughout the tunable frequency range.
    Type: Grant
    Filed: January 26, 1976
    Date of Patent: January 25, 1977
    Assignee: RCA Corporation
    Inventors: Pang-Ting Ho, Arye Rosen
  • Patent number: 3974459
    Abstract: Disclosed is a millimeter wave waveguide structure adapted for operation with negative resistance devices, such as solid state avalanche breakdown diodes, at frequencies up to about 170 GHz or higher. A central portion of the structure is formed by a cylindrical metallic impedance transformer and bias pin which has a major face thereof substantially parallel to a common lower waveguide wall of the structure. A negative resistance device is DC coupled between this common waveguide wall and one edge of the impedance transformer, so that the impedance transformer also provides the required DC bias to the negative resistance device. Other portions of the waveguide structure include a first upper waveguide wall, immediately adjacent one side of the impedance transformer, and this wall, together with the common lower waveguide wall, forms a tuning cavity into which a sliding tuning short is positioned.
    Type: Grant
    Filed: June 23, 1975
    Date of Patent: August 10, 1976
    Assignee: Hughes Aircraft Company
    Inventor: Kenneth P. Weller
  • Patent number: 3946336
    Abstract: This microwave circuit incorporates a transistor structure that provides either a two port amplifier or an injection frequency locked oscillator. This circuit eliminates circulators employed with Gunn and Impatt diode amplifiers and injection frequency locked oscillators. The collector-base junction is reverse biased so that the collector region functions either in the Impatt mode or in the transferred electron mode. An RF input signal is applied across the forward biased emitter-base junction. With a load across the collector-base junction having a conductance equal to the absolute value of the negative conductance generated by the collector region, the circuit functions as an oscillator at a frequency which is injection locked to the frequency of the input signal. With a load of increased conductance to suppress oscillations, i.e. overload the collector region, the circuit functions as an amplifier.
    Type: Grant
    Filed: February 26, 1975
    Date of Patent: March 23, 1976
    Assignee: International Standard Electric Corporation
    Inventors: Jocelyn Froom, John Edward Carroll