L-c Oscillator Type Patents (Class 332/141)
  • Patent number: 7847646
    Abstract: A carrier generator for generating a carrier at a frequency of interest in a wireless communications system comprises an oscillator exhibiting a first impedance, the oscillator comprising an energy storage tank configured to generate a periodic signal, the energy storage tank including at least one inductor and at least one capacitor, and an amplifier coupled with the energy storage tank, the amplifier being configured to amplify an amplitude of the periodic signal, an antenna exhibiting a second impedance smaller than the first impedance, and a network coupled between the oscillator and the antenna, the network including at least one inductor or at least one capacitor and being configured to provide a third impedance such that a resultant impedance of the second impedance and the third impedance as viewed from the oscillator toward the antenna is large enough to facilitate the oscillator to generate the carrier at the frequency of interest.
    Type: Grant
    Filed: May 27, 2008
    Date of Patent: December 7, 2010
    Assignee: FAVEPC, Inc.
    Inventors: Chun-Liang Tsai, Shao-Chang Chang
  • Patent number: 7567641
    Abstract: Because of the natural ability to reject clock jitter, the SRC circuits include an internal oscillator to provide an operating clock signal. The internal oscillator can be operated independently of any external frequency control signal, including input and output frame clocks. The internal oscillator can be implemented as a relatively low-cost fixed frequency oscillator. The use of a relatively low precision, inexpensive internal oscillator in an SRC circuit reduces the overall cost of SRC circuits while providing acceptable performance. Accordingly, reducing costs of SRC circuits also has a positive cost/benefit affect on the digital signal processing systems that use SRC circuits.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: July 28, 2009
    Assignee: Cirrus Logic, Inc.
    Inventor: Gautham D. Kamath
  • Patent number: 7388446
    Abstract: A variable capacitor modulator for use in a voltage controlled oscillator, includes a differential varactor block, coupling capacitors for connecting nodes of the varactor block to a tank circuit, and an element connected between the respective nodes and ground to trim the gain of the variable capacitor modulator.
    Type: Grant
    Filed: February 10, 2005
    Date of Patent: June 17, 2008
    Assignee: Zarlink Semiconductor Ab
    Inventors: Viatcheslav Igorevich Souetinov, Alexander Alekseevich Krasin, Alexander Victorovich Koulakov
  • Patent number: 7102454
    Abstract: A VCO system embodying the features of the present invention includes a frequency tuning circuit, a modulation circuit coupled in a parallel fashion with the frequency tuning circuit, a band tuning circuit coupled with the frequency tuning circuit in a parallel fashion having at least one switching circuit, a core circuit coupled with the frequency tuning circuit, the modulation circuit, and the band tuning circuit, wherein upon asserting a switching signal and upon adjusting a frequency turning signal, a frequency tuning bias signal, and a band tuning signal, the switching circuit is enabled for configuring the band tuning circuit to join the frequency tuning circuit for adjusting a predetermined output frequency based on a total inductance and a total capacitance provided by the core circuit, the frequency tuning circuit, the modulation circuit and the band tuning circuit.
    Type: Grant
    Filed: January 31, 2005
    Date of Patent: September 5, 2006
    Assignee: VIA Technologies, Inc.
    Inventors: Bour-Yi Sze, Chih-Long Ho, Nean-Chu Cheng
  • Patent number: 7065326
    Abstract: A high data rate communication system operating at frequencies greater than 70 MHz and at data rates of about 1.25 Gbps or greater. Preferred embodiments include modulators with a resonant LC circuit including a diode which is back-biased for “off” (i.e., no transmit) and forward biased for “on” (or transmit). The modulator is a part of high performance transceivers for wireless, millimeter wave communications links. A preferred embodiment provides a communication link of more than eight miles which operates within the 71 to 76 GHz portion of the millimeter spectrum and provides data transmission rates of 1.25 Gbps with bit error rates of less than 10?10 . A first transceiver transmits at a first bandwidth and receives at a second bandwidth both within the above spectral range. A second transceiver transmits at the second bandwidth and receives at the first bandwidth.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: June 20, 2006
    Assignee: Trex Enterprises Corporation
    Inventors: John Lovberg, Richard Chedester, Paul Johnson, Louis Slaughter
  • Patent number: 6993315
    Abstract: A resonant tunneling diode or diode array oscillator (10) including a resonant diode (11) is coupled to a millimeter-wave source (14) and a quench generator (16) for periodically quenching the oscillations so that the average oscillation time of the oscillator is proportional to signal strength of the source (14). The signal source can be from an antenna such as a dipole or tapered slot line antenna.
    Type: Grant
    Filed: November 21, 2000
    Date of Patent: January 31, 2006
    Assignee: Raytheon Company
    Inventor: Gary Frazier
  • Patent number: 6784753
    Abstract: The invention relates to a method for modulating an output voltage of a transmitter circuit comprising a voltage controlled oscillator, a digital/analog converter and an antenna circuit, the method comprising the method comprising sending an output signal of sufficient power from the voltage controlled oscillator directly to the antenna circuit and directly modulating a frequency of the output signal of the voltage controlled oscillator. The invention furthermore relates to a transmitter circuit comprising a voltage controlled oscillator having a tank circuit, a digital/analog converter and an antenna circuit, wherein the voltage controlled oscillator is adapted to send an output signal of sufficient power directly to the antenna circuit and wherein the digital/analog converter is arranged to modulate an output frequency of the voltage controlled oscillator.
    Type: Grant
    Filed: May 13, 2002
    Date of Patent: August 31, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Dominicus Martinus Wilhelmus Leenaerts, Eise Carel Dijkmans
  • Patent number: 6353370
    Abstract: A method and apparatus for modulation of a voltage-controlled oscillator (VCO). The VCO receives a tuning control voltage for adjusting a center frequency of an output periodic signal formed by the VCO. In addition, the VCO receives a modulation control voltage for modulating the output periodic signal by a content-carrying signal according to frequency modulation techniques. A frequency deviation obtained in the output periodic signal in response to changes in the modulation control voltage is linearized by forming the modulation control voltage as the result of a linear correction polynomial. A linear correction circuit forms the modulation control voltage. More particularly, a first amplifier having a gain of K1 receives the tuning control voltage. A first summing block then receives the output of the first amplifier and adds the constant K0. A second amplifier having a gain of m receives the content-carrying signal.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: March 5, 2002
    Assignee: Micro Linear Corporation
    Inventors: Robert Cox, Gwilyn Luff
  • Patent number: 5870005
    Abstract: A broadcast transmitter for generating low power modulated signals, especially for a wireless speaker system. A signal source such as a source of composite audio signals including left and right audio signals and a pilot signal are applied to a radio frequency signal oscillator. The radio frequency signal oscillator includes a bipolar transistor connected in a common base configuration, and having a stripline element as a frequency determinative component in the collector circuit of the bipolar transistor. The modulating signal is applied to the base of the bipolar transistor which modulates the collector junction capacitance of the transistor thereby frequency modulating the signal produced by the oscillator. Varactor tuning is provided for setting a nominal frequency of oscillation.
    Type: Grant
    Filed: July 3, 1997
    Date of Patent: February 9, 1999
    Inventor: Shiu Hung Cheung
  • Patent number: 5815218
    Abstract: A circuit device provided in a video signal processing apparatus. The circuit device includes a tuner for tuning a television signal, an IF amplifier for demodulating the television signal, and an RF converter having an RF oscillator for modulating video and audio signals into a television signal in a VHF band. The tuner, IF amplifier and RF converter are accommodated in a shield case. Further, the circuit device includes a circuit including a resonance circuit having a coil and a capacitor for controlling an oscillation frequency of the RF oscillator and a switch for switching a parameter of the resonance circuit to vary the oscillation frequency.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: September 29, 1998
    Assignee: Funai Electric., Ltd
    Inventor: Osamu Maeda
  • Patent number: 5564100
    Abstract: A frequency modulator (100) is provided which includes a VCO (200) having a modulation varactor (122) coupled to its output (128). The VCO (200) includes a resonator stage (112) coupled to an amplifier stage comprising a transistor (118). Coupling of the varactor (122) and the resonator stage (112) is provided via the phase collector capacitance (C.mu.) of the transistor (118).
    Type: Grant
    Filed: May 1, 1995
    Date of Patent: October 8, 1996
    Assignee: Motorola, Inc.
    Inventors: Philip M. Huang, John K. McKinney
  • Patent number: 5329243
    Abstract: A noise adaptive automatic gain control circuit (100) includes an automatic gain control amplifier (105) for automatically adjusting the gain of the circuit (100) in response to an input signal applied to the input. A detector (135) is provided for detecting the presence of any background noise that may be present. Further, a voltage generator (126), a comparator (124), and a microcomputer (150) is provided for dynamically adjusting the gain of the AGC amplifier (105) to substantially prevent the amplification of the background noise. In other aspects of the present invention, a voice lull detector (140) detects voice lulls (402) in the input signal applied to the input. Further, a programmable amplifier (120) substantially maintains the gain of the AGC amplifier (105) to a constant level during voice lulls (402) to prevent excessive amplification.
    Type: Grant
    Filed: September 17, 1992
    Date of Patent: July 12, 1994
    Assignee: Motorola, Inc.
    Inventor: Wan F. Tay
  • Patent number: 5222016
    Abstract: According to this invention, a frequency converter comprises a frequency mixer (11) formed in a semiconductor integrated circuit (10), an impedance conversion/signal amplitude limit differential amplifier (12) formed in the semiconductor integrated circuit and connected to the output of the frequency mixer, a first frequency mixing output terminal (14) connected to an output terminal of the frequency mixer and serving as an external terminal of the semiconductor integrated circuit, and a second frequency mixing output terminal (15) connected to an output terminal of the differential amplifier and serving as an external terminal of the semiconductor integrated circuit.
    Type: Grant
    Filed: July 29, 1991
    Date of Patent: June 22, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Susumu Matsumoto, Masaru Hashimoto