Patents Examined by Siegfried Grimm
  • Patent number: 5497121
    Abstract: A data detection circuit (30) for automatically adjusting to an FSK modulated signal to set a proper trip point for differentiating logic high and low. The detection circuit (30) includes: A demodulator (32) which converts a received FSK modulated signal to voltage levels corresponding to respective frequencies of the modulated signal. A voltage clamp circuit (42) which samples and stores a voltage level of the output of the demodulator (32) and provides a trip point voltage level representing a sum of the stored voltage level and a fixed voltage offset. A comparator (50) which compares the trip point voltage to the voltage levels at the output of the demodulator (32) to provide a logic output signal representing detected digital data signals.
    Type: Grant
    Filed: November 30, 1994
    Date of Patent: March 5, 1996
    Assignee: Texas Instruments Incorporated
    Inventor: Loek D'Hont
  • Patent number: 5451899
    Abstract: In a direct conversion receiver in which received radio frequency signals are mixed with quadrature local oscillator signals in I and Q channels, the output signals from the mixers are applied to a phase detector by way of respective frequency tracking filters to reduce the noise bandwidth and improve the sensitivity.
    Type: Grant
    Filed: September 8, 1994
    Date of Patent: September 19, 1995
    Assignee: Plessey Semiconductors Limited
    Inventor: Rodney J. Lawton
  • Patent number: 5025229
    Abstract: A Colpitts oscillator has an integrated circuit. The integrated circuit includes a transistor having an equivalent large size, a bypass capacitor connected between a collector of the transistor and a ground, a first feedback capacitor connected between a base and an emitter of the transistor, a second feedback capacitor connected between the emitter of the transistor and the ground, and an emitter follower connected to the emitter of the transistor. In a package, a stray reactance and a bonding wire are designed so as to agree with an element value and a Q value which can be used as parts of a resonator. A surface elastic wave resonator disposed outside the integrated circuit is connected between the base of the transistor and the ground. The oscillator is voltage controlled by a variable capacitance diode connected in series with the resonator.
    Type: Grant
    Filed: May 24, 1990
    Date of Patent: June 18, 1991
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Makoto Hasegawa, Kazuaki Takahashi, Mitsuo Makimoto, Masao Takahashi, Takayuki Shimazu
  • Patent number: 4843348
    Abstract: A monolithically integrable amplitude-controllable oscillator amplifier circuit includes a differential amplifier. The bases of first, second and third transistors are acted upon by a direct voltage. A first capacitor connects the base of the second transistor to a reference potential. A frequency-determining circuit element is connected to the base of a first transistor, the collector of the second transistor and the oscillator amplifier. The collector of the first transistor is connected directly to the emitter of the third transistor forming a cascode circuit. The collector of the third transistor is connected to a first potential. The collector of the second transistor forms an amplifier output. A first resistor is connected between the collector of the second transistor and a second potential.
    Type: Grant
    Filed: July 18, 1988
    Date of Patent: June 27, 1989
    Assignee: Siemens Aktiengesellschaft
    Inventor: Josef Fenk
  • Patent number: 4189685
    Abstract: A transistor oscillator circuit wherein the load current applied to animal tissue treatment electrodes is fed back to the transistor. Removal of load is sensed to automatically remove feedback and stop oscillations. A thermistor on one treatment electrode senses temperature, and by means of a control circuit controls oscillator transistor current.
    Type: Grant
    Filed: March 14, 1978
    Date of Patent: February 19, 1980
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: James D. Doss
  • Patent number: 3980969
    Abstract: A phase-locking network at the receiving end of a transmission channel carries an incoming wave of predetermined frequency matching the operating frequency of a local oscillator the incoming wave and the locally generated oscillations being fed to respective inputs of a phase comparator producing a control voltage delivered through a low-pass filter to the oscillator for reducing any existing phase difference. The signal path between the phase comparator and the oscillator includes one or more nonlinear impedance elements, either within the filter or in cascade therewith, which lowers the effective series resistance of the path in the presence of a high control voltage and thereby increases its bandwidth during an acquisition period as compared with steady-state operation.
    Type: Grant
    Filed: April 14, 1975
    Date of Patent: September 14, 1976
    Assignee: CSELT - Centro Studi e Laboratori Telecommunicazioni SpA
    Inventor: Renato Stengel