Variable Capacitor Tuned Patents (Class 455/197.2)
  • Patent number: 10205809
    Abstract: A method for manufacturing an electronic device, according to the present disclosure, may include: detecting positions of one or more heat sources, which are disposed in a printed circuit board or in a display of the electronic device, or a path of the heat that is diffused from the heat sources; selecting a heat radiating structure to correspond to the positions of the heat sources or the diffusion path; selecting an adiabatic member or a heat radiating member, which is disposed based the selected heat radiating structure to block or radiate the heat transferred from the heat source; and forming the selected heat radiating structure or disposing the selected adiabatic member or heat radiating member on the periphery of the heat source or on the diffusion path.
    Type: Grant
    Filed: October 7, 2016
    Date of Patent: February 12, 2019
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hae-Jung Yang, Seung-Joo Lee, Kwang-Eun Go, Kang-Sik Kim, Jae-Hoon Woo, Jong-Min Lee
  • Patent number: 9793055
    Abstract: According to one embodiment, an electronic device includes an underlying region, a variable capacitor including fixed electrodes and movable electrodes alternately arranged in a direction not perpendicular to a main surface of the underlying region, and a protective film which covers the variable capacitor and includes a conductive portion electrically connected to the fixed electrodes and having a hole.
    Type: Grant
    Filed: September 9, 2015
    Date of Patent: October 17, 2017
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akira Fujimoto, Naofumi Nakamura, Tamio Ikehashi
  • Patent number: 9002306
    Abstract: A method includes receiving a desired channel indication in a radio tuner, determining a band of operation in which the channel is located, and if the channel is within a first band coupling multiple inductors into a resonant tank, and if the desired channel is within a second band coupling a single inductor into the resonant tank.
    Type: Grant
    Filed: August 5, 2014
    Date of Patent: April 7, 2015
    Assignee: Silicon Laboratories Inc.
    Inventors: Jing Li, Dan B. Kasha, Aslamali Rafi
  • Patent number: 8996080
    Abstract: A radio-frequency (RF) device for a wireless communication device includes a grounding element, an antenna, a first DC blocking element for cutting off a direct-current (dc) signal route between a grounding terminal of the antenna and the grounding element, a capacitive sensing unit capable of using a radiating element of the antenna to sense an environment capacitance within a specific range, a second DC blocking element electrically connected between the radiating element and the feed-in element for blocking a dc signal path from the radiating element to the feed-in element, and a high-frequency blocking element electrically connected between the radiating element and the capacitive sensing unit for blocking a high-frequency signal path from the radiating element to the capacitive sensing unit.
    Type: Grant
    Filed: August 12, 2013
    Date of Patent: March 31, 2015
    Assignee: Wistron NeWeb Corporation
    Inventors: Shang-Sian You, Kuan-Hsueh Tseng
  • Patent number: 8862083
    Abstract: To adjust a tuning frequency without an output being muted while an oscillation frequency is adjusted. A tuning circuit includes a pair of an inductor and a tuning variable capacitor unit, adjusts a tuning frequency by changing a capacitance of the tuning variable capacitor unit, and obtains a tuning signal having a limited band from a received signal. The tuning circuit includes an oscillating inductor that passes a current corresponding to the tuning signal, an oscillating variable capacitor unit that adjusts the oscillation frequency of a system including the oscillating inductor, and a controller that changes a capacitance of the oscillating variable capacitor unit correspondingly to a desired tuning frequency while adjusting the capacitance such that the oscillation frequency corresponds to the desired tuning frequency, and adjusts a capacitance of the tuning variable capacitor unit in accordance with the adjusted capacitance of the oscillating variable capacitor unit.
    Type: Grant
    Filed: June 4, 2013
    Date of Patent: October 14, 2014
    Assignee: Semiconductor Components Industries, LLC
    Inventors: Satoru Sekiguchi, Shinya Inaba, Toru Odajima
  • Patent number: 8818309
    Abstract: A method includes receiving a desired channel indication in a radio tuner, determining a band of operation in which the channel is located, and if the channel is within a first band coupling multiple inductors into a resonant tank, and if the desired channel is within a second band coupling a single inductor into the resonant tank.
    Type: Grant
    Filed: March 28, 2011
    Date of Patent: August 26, 2014
    Assignee: Silicon Laboratories Inc.
    Inventors: Jing Li, Dan B. Kasha, Aslamali A. Rafi
  • Patent number: 8781396
    Abstract: A contactless receiver is provided with a receiving section and a rectification section. The receiving section has a resonant circuit including a resonant capacitor having a variable capacitance element formed with a ferroelectric material, a capacitance of the variable capacitance element changing according to a received voltage at a predetermined frequency, and a resonance coil connected to the resonant capacitor. The rectification section converts an alternating current voltage output from the receiving section into a direct current voltage.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: July 15, 2014
    Assignee: Dexerials Corporation
    Inventors: Masayoshi Kanno, Kazutaka Habu, Makoto Watanabe, Toshiaki Yokota
  • Patent number: 8275336
    Abstract: An oscillator circuit having a source of an oscillating signal, a tank circuit including an inductor and a capacitor, and a discretely switchable capacitance module configured to control an amount of capacitance in the oscillator circuit. The discretely switchable capacitance module includes, in one embodiment, a capacitor coupled between a first node and a second node, a switch, having a control node, coupled between the second node and a third node; and a DC feed circuit, having a first end coupled to the second node and a second end configured to receive a first or second control signal. The control node of the switch is tied to a predetermined bias voltage. When the first control signal is applied, the capacitor is coupled between the first node and the third node via the switch such that the capacitor is coupled in parallel with the capacitor of the tank circuit, and when the second control signal is applied the capacitor is decoupled from the tank circuit.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: September 25, 2012
    Assignee: Richwave Technology Corp.
    Inventor: Chen Tse-Peng
  • Patent number: 8260200
    Abstract: A non-contact wireless communication apparatus and a mobile terminal apparatus are provided.
    Type: Grant
    Filed: November 14, 2008
    Date of Patent: September 4, 2012
    Assignee: Sony Mobile Communications Japan, Inc.
    Inventors: Kanjiro Shimizu, Toshiyuki Takahashi
  • Patent number: 8233864
    Abstract: Disclosed herein is a signal receiving apparatus including: a resonance section configured to receive an input signal at a variable resonance frequency; a signal supplying section configured to supply an electrical signal having a desired reception frequency to the resonance section; a mixture section configured to mix a resonance signal, which is output by the resonance section when the resonance section receives the electrical signal from the signal supplying section, with a switching signal having the desired reception frequency; and a control section configured to change a resonance characteristic of the resonance section and measure the phases of mixed signals output by the mixture section before and after the resonance characteristic changing operation to control the resonance frequency of the resonance section in order to change the resonance frequency in a direction to reduce a difference between the phases of the mixed signals before and after the resonance characteristic changing operation.
    Type: Grant
    Filed: March 3, 2011
    Date of Patent: July 31, 2012
    Assignee: Sony Corporation
    Inventor: Hitoshi Tomiyama
  • Patent number: 8219038
    Abstract: The present invention relates to a portable terminal, and to a method and apparatus for improving broadcasting reception performance of the portable terminal by filtering a transmission frequency of a radio frequency unit introduced to a broadcasting reception path without experiencing broadcast signal loss. The filtering can be achieved using a filter that includes a variable capacitor in the broadcasting reception path. Accordingly, the transmission frequency of the radio frequency unit may be filtered without a broadcast signal loss. A capacitance of the variable capacitor may be controlled according to the broadcast channel.
    Type: Grant
    Filed: July 27, 2009
    Date of Patent: July 10, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sung Won Kim, Jae Min Seo, Jung Su Lee, Jae Kwang Lee, Jang Uk Lee
  • Patent number: 8000668
    Abstract: Structurally simple transmit/receive circuits for hearing devices are to be able to be deployed for higher frequencies as well. It is therefore proposed according to the invention that at least two PIN diodes should be connected in an anti-parallel manner between the receive oscillating circuit and the amplifier connected thereto to protect the amplifier. A capacitance diode can optionally be expanded so that larger component tolerances can be permitted for the circuit.
    Type: Grant
    Filed: June 26, 2007
    Date of Patent: August 16, 2011
    Assignee: Siemens Audiologische Technik GmbH
    Inventors: Mihail Boguslavskij, Peter Nikles, Jürgen Reithinger, Ulrich Schätzle
  • Patent number: 7962115
    Abstract: A circuit with programmable signal bandwidth is provided. The circuit includes a first charge and discharge device, a first reset device, and a first variable capacitor device. The first reset device is coupled to the first charge and discharge device, and the first variable capacitor device is coupled to the first charge and discharge device. The first reset device is controlled by a discharge enable signal and used to provide a first discharge path. When the discharge enable signal turns off the first reset device, the first variable capacitor device generates a first total equivalent capacitor to the first charge and discharge device according to n reference signals, and n is an integer greater than 0.
    Type: Grant
    Filed: February 5, 2008
    Date of Patent: June 14, 2011
    Assignee: Industrial Technology Research Institute
    Inventors: Ming-Feng Huang, Ming-Hau Tseng
  • Patent number: 7937056
    Abstract: A variable capacitance device has a piezoelectric driving part, a movable electrode, a fixed electrode, a dielectric film and a driving control unit. The piezoelectric driving part has a piezoelectric film, an upper electrode disposed on a top surface of the piezoelectric film, a lower electrode disposed on an undersurface of the piezoelectric film and electrode slits which separate the upper electrode and the lower electrode into two, respectively. The movable electrode is provided via the electrode slits at one end of the piezoelectric driving part. The fixed electrode is disposed opposite to the movable electrode via a gap. The dielectric film is disposed opposite to the movable electrode via the gap and provided on the fixed electrode. The driving control unit adjusts a distance between the movable electrode and the fixed electrode to reduce a fluctuation of a predetermined capacitance of a variable capacitor formed between the variable electrode and the fixed electrode.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: May 3, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuhiko Itaya, Hiroshi Yoshida, Takashi Kawakubo
  • Patent number: 7860478
    Abstract: Provided is a poly-phase filter capable of removing an image frequency of a terrestrial digital multimedia broadcasting (T-DMB) receiver in a low intermediate frequency (IF) structure applied to a mobile communication terminal and a receiver having the poly-phase filter. The poly-phase filter includes: a calibration control block for generating first and second filter characteristic control signals which determine electrical characteristics of the filter in response to a control signal including instructions for changing the characteristics of the poly-phase filter and holding the changed values; and a poly-phase filter block for performing filtering on a plurality of input signals having different phases from each other in response to the first and second filter characteristic control signals. Accordingly, the poly-phase filter has advantages of having constant electrical characteristics regardless of changes in a manufacturing process and temperature and a high-performance image rejection function.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: December 28, 2010
    Assignee: FCI, Inc.
    Inventors: Kyoo Hyun Lim, Sun Ki Min
  • Patent number: 7756500
    Abstract: An integrated front-end filter for a tuner provides an array of from several to a multitude of passbands, each for passing at least one but less than all channels designated in a band of frequencies. Each passband is exclusively selectable. The integrated front end filter includes at least one active filter unit with an active reactance element in either of fixed and variable filter configurations and a decoder coupled to said at least one active filter unit and being responsive to a control signal for selecting a one of the passbands. In one example a multitude of active filter units of fixed filter configuration provide the multitude of passbands. Each data is stored at a predetermined location and reproduced in response to a corresponding control data signal from a tuner controller. Each data characterizes one of the plurality of passbands. The filter element is switchable from one passband to another in response to the control data signal.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: July 13, 2010
    Assignee: SiGe Semiconductor Inc.
    Inventors: Stefan Fulga, David Rahn
  • Patent number: 7720452
    Abstract: A reception circuit can receive a plurality of standard time signals and has a reception means for selectively receiving and demodulating any one of the plural standard time signals, and a control means for outputting a control signal that controls the reception means. The reception means includes a signal amplifier unit for amplifying a reception signal representing the received standard time signal; a signal extraction unit for extracting a signal of a specific frequency from the amplified reception signal; a rectifier unit for rectifying the extracted signal of the specific frequency; and a demodulation unit for demodulating the rectified signal of the specific frequency.
    Type: Grant
    Filed: June 14, 2007
    Date of Patent: May 18, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Fumiaki Miyahara, Teruhiko Fujisawa
  • Patent number: 7643809
    Abstract: Using low impedance switches and coupling to a virtual ground, one or more capacitors are selectively switched into or out of an inductive-capacitive resonant circuit portion of an integrated circuit filter to alter the resonant frequency based on a phase difference between the resonant frequency and a reference frequency. The capacitors are sized for a sequence of total capacitances proceeding by halves or doubles between values corresponding to minimum and maximum desired frequency adjustments, allowing a binary count of pulses representative of the phase difference to address the correct combination of capacitors. An exact or ratioed replica of the inductive-capacitive resonant circuit, controlled by the same capacitance selection signal, may be used as a frequency-selective amplifier load or matching network, or to form a ladder filter.
    Type: Grant
    Filed: September 6, 2005
    Date of Patent: January 5, 2010
    Assignee: National Semiconductor Corporation
    Inventor: Daniel R. Meacham
  • Patent number: 7515887
    Abstract: In a radio-controlled timepiece, a tuning unit outputs a signal corresponding to a radio signal. An amplifier unit amplifies a signal output from the tuning unit. A receiving unit that extracts the time code from the amplified signal has a filter unit that selectively allows one of frequency signals to pass therethrough. A time-correcting unit acquires current time information from the extracted time code to correct a current time clocked by a clock unit. A control unit detects a voltage level of a signal output from the amplifier unit at two or more points while changing a capacitance value of a variable-capacitance unit of the tuning unit, uses, as a tuning point, a point meeting a given requirement among the points where the voltage level has been detected, and sets the capacitance value of the variable-capacitance unit at the tuning point as a capacitance value to receive the time code when it is judged that a time code has been output from the receiving unit at the tuning point.
    Type: Grant
    Filed: November 23, 2005
    Date of Patent: April 7, 2009
    Assignee: Seiko Instruments Inc.
    Inventor: Yoritaka Saitoh
  • Patent number: 7454182
    Abstract: A high frequency part, which amplifies a high frequency signal outputted from an intermediate frequency part and supplies to an antenna, is equipped with a gain controller with switch function. The gain controller with switch function comprises an attenuator with switch function has a function of switching a selected band between two bands outputted from the intermediate frequency part and controlling the gain of the high frequency signal in the selected band. The attenuator with switch function comprises a first variable resistor which connects a signal input part with a signal output part and a second variable resistor which is disposed parallel to said first variable resistor and connects a signal input part with a signal output part. The first and the second variable resistors are controlled by a common gain control voltage and set such that the gain control voltage ranges, which are for changing the resistor values, will not overlap with each other.
    Type: Grant
    Filed: June 5, 2007
    Date of Patent: November 18, 2008
    Assignee: Panasonic Corporation
    Inventors: Masahiko Inamori, Takashi Yamamoto, Masao Nakayama, Kaname Motoyoshi
  • Patent number: 7376400
    Abstract: A communications system comprising a processor, a variable oscillator, a radio frequency (RF) quadrature demodulator, a variable capacitor, a continuous-time, sigma-delta analog-to-digital converter (ADC), and a frequency divider, all integrated on a single semiconductor chip. The ADC samples the RF quadrature demodulator output. The processor sets the communications system frequency by controlling the oscillator, the frequency divider and the variable capacitor.
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: May 20, 2008
    Assignee: Texas Instruments Incorporated
    Inventors: Abdellatif Bellaouar, Paul-Aymeric Fontaine
  • Publication number: 20070281646
    Abstract: A variable capacitance device has a piezoelectric driving part, a movable electrode, a fixed electrode, a dielectric film and a driving control unit. The piezoelectric driving part has a piezoelectric film, an upper electrode disposed on a top surface of the piezoelectric film, a lower electrode disposed on an undersurface of the piezoelectric film and electrode slits which separate the upper electrode and the lower electrode into two, respectively. The movable electrode is provided via the electrode slits at one end of the piezoelectric driving part. The fixed electrode is disposed opposite to the movable electrode via a gap. The dielectric film is disposed opposite to the movable electrode via the gap and provided on the fixed electrode. The driving control unit adjusts a distance between the movable electrode and the fixed electrode to reduce a fluctuation of a predetermined capacitance of a variable capacitor formed between the variable electrode and the fixed electrode.
    Type: Application
    Filed: May 30, 2007
    Publication date: December 6, 2007
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kazuhiko Itaya, Hiroshi Yoshida, Takashi Kawakubo
  • Patent number: 7263339
    Abstract: The invention relates to a tuner for converting a radio frequency signal into an intermediate frequency signal, said tuner comprising a voltage converter supplying a control signal, a mixer associated with an oscillator which is voltage-controlled by said control signal. The invention is characterized in that said voltage converter comprises: an auto-oscillating circuit generating an alternating voltage signal of a variable level, rectifying means for supplying a direct voltage signal of a variable level based on said alternating voltage signal of a variable level, an additional circuit for reducing the variations of the attenuation coefficient of said auto-oscillating circuit, said additional circuit receiving said direct voltage signal of a variable level and supplying said control signal. The invention provides an inexpensive solution having an improved performance in terms of spectral purity, ease of implementation and stability of control of said intermediate frequency signal.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: August 28, 2007
    Assignee: NXP B.V.
    Inventor: Xavier Pruvost
  • Patent number: 7245895
    Abstract: A high frequency part, which amplifies a high frequency signal outputted from an intermediate frequency part and supplies to an antenna, is equipped with a gain controller with switch function. The gain controller with switch function comprises an attenuator with switch function has a function of switching a selected band between two bands outputted from the intermediate frequency part and controlling the gain of the high frequency signal in the selected band. The attenuator with switch function comprises a first variable resistor which connects a signal input part with a signal output part and a second variable resistor which is disposed parallel to said first variable resistor and connects a signal input part with a signal output part. The first and the second variable resistors are controlled by a common gain control voltage and set such that the gain control voltage ranges, which are for changing the resistor values, will not overlap with each other.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: July 17, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masahiko Inamori, Takashi Yamamoto, Masao Nakayama, Kaname Motoyoshi
  • Patent number: 7209188
    Abstract: An intermediate-frequency circuit includes a mixer for converting a received TV signal to an intermediate-frequency signal; an intermediate-frequency amplifier for amplifying the intermediate-frequency signal; an intermediate-frequency tuning circuit for tuning to the intermediate-frequency signal, the intermediate-frequency tuning circuit being interposed between the mixer and the intermediate-frequency amplifier; and a trap circuit interposed between the mixer and the intermediate-frequency tuning circuit or between the intermediate-frequency tuning circuit and the intermediate-frequency amplifier, wherein a trap frequency of the trap circuit can be changed in a region outside a video intermediate frequency.
    Type: Grant
    Filed: April 27, 2004
    Date of Patent: April 24, 2007
    Assignee: Alps Electric Co., Ltd.
    Inventor: Akira Kawamura
  • Patent number: 7155195
    Abstract: A direct conversion receiver including a filtering system for improving signal reception in the receiver is disclosed. In one embodiment, the direct conversion receiver comprises a first filter adapted to receive a plurality of receive signals comprising a receive band. The first filter is configured to attenuate a frequency range of the receive band to de-emphasize signals within of the frequency range. The direct conversion receiver also comprises a second filter coupled to a signal processing logic output and is configured to amplify the signals in the frequency range of the receive band, the signal processing logic being coupled to the output of the first filter and configured to substantially attenuate a plurality of unwanted signals in the receive band.
    Type: Grant
    Filed: June 14, 2002
    Date of Patent: December 26, 2006
    Assignee: Skyworks Solutions, Inc.
    Inventor: John E. Vasa
  • Patent number: 7031683
    Abstract: A calibration circuitry includes an adjustable capacitor, a voltage generator, a reference voltage generator, and a controller. The reference voltage generator provides a reference voltage. The voltage generator provides a measurement voltage that depends on the capacitance of the adjustable capacitor. The capacitance of the adjustable capacitor varies in response to a control signal. The controller provides the control signal based on the relative values of the reference voltage and the measurement voltage.
    Type: Grant
    Filed: February 26, 2002
    Date of Patent: April 18, 2006
    Assignee: Silicon Laboratories Inc.
    Inventors: G. Diwakar Vishakhadatta, Donald A. Kerth, Russell Croman, Jeffrey W. Scott, Richard T. Behrens, G. Tyson Tuttle, Vishnu S. Srinivasan
  • Patent number: 6940358
    Abstract: Using low impedance switches and coupling to a virtual ground, one or more capacitors are selectively switched into or out of an inductive-capacitive resonant circuit portion of an integrated circuit filter to alter the resonant frequency based on a phase difference between the resonant frequency and a reference frequency. The capacitors are sized for a sequence of total capacitances proceeding by halves or doubles between values corresponding to minimum and maximum desired frequency adjustments, allowing a binary count of pulses representative of the phase difference to address the correct combination of capacitors. An exact or ratioed replica of the inductive-capacitive resonant circuit, controlled by the same capacitance selection signal, may be used as a frequency-selective amplifier load or matching network, or to form a ladder filter.
    Type: Grant
    Filed: February 8, 2002
    Date of Patent: September 6, 2005
    Assignee: National Semiconductor Corporation
    Inventor: Daniel R. Meacham
  • Publication number: 20040214543
    Abstract: A microelectronic device includes a substrate, a variable capacitor including a driving mechanism for varying capacitance stored by a pair of electrodes formed in a main surface of the substrate, a plurality of fixed capacitors having fixed capacitance stored by a plurality of pairs of electrodes formed in an opposite side of the main surface, wiring for electrically connecting the variable capacitor and the fixed capacitors, and switches disposed in the main surface of the substrate to electrically connect the variable capacitor and a capacitor or capacitors selected from the plurality of fixed capacitors.
    Type: Application
    Filed: February 19, 2004
    Publication date: October 28, 2004
    Inventors: Yasuo Osone, Noriyo Nishijima, Norio Nakazato
  • Publication number: 20040157573
    Abstract: A method and circuit for compensating for a DC offset generated in a signal processing apparatus are disclosed.
    Type: Application
    Filed: February 6, 2004
    Publication date: August 12, 2004
    Inventors: Jung-Hwan Lee, Jin-Kyu Lim, Min-Su Jeong, Bon-Kee Kim, Bo-Eun Kim
  • Patent number: 6747522
    Abstract: A method of tuning a DCXO includes the step of providing a coarse tuning array and a fine tuning array of capacitors fabricated on the same integrated circuit die. The coarse array is adjusted until the difference between a desired frequency and the output frequency corresponds to a change in capacitance no greater than half the range of the fine tuning array. In one embodiment, the fine tuning array is adjusted to mid-range before adjusting the coarse tuning array. A DCXO apparatus includes at least one integrated circuit segmented switched capacitor network providing a capacitance that is a nonmonotonic function of a composite input code. The segmented switched capacitor network includes parallel coupled binary weighted and thermometer coded switched capacitor networks for coarse and fine tuning, respectively.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: June 8, 2004
    Assignee: Silicon Laboratories, Inc.
    Inventors: David M. Pietruszynski, Douglas R. Frey
  • Publication number: 20030216129
    Abstract: A circuit in a wireless transmitter or other apparatus is automatically calibrated using a calibration circuit to accommodate provide a desired characteristic such as a filter response, where the component values of the filter circuit may vary such as in an integrated circuit. In one embodiment, the calibration circuit is coupled to one or more adjustable capacitors in the filter circuit to select a capacitor value so that the filter circuit exhibits the desired filter response. In one particular embodiment, the adjustable capacitor is charged in an RC circuit for each clock cycle at power up. The value of the adjustable capacitor is changed for each clock cycle until the capacitor charges to a level greater than or equal to predetermined reference voltage. When the capacitor is charged to a predetermined reference voltage, a desired capacitance value is indicated, and the adjustable capacitor is maintained at the desired capacitance value to provide the desired filter output.
    Type: Application
    Filed: May 16, 2002
    Publication date: November 20, 2003
    Inventors: Waleed Khalil, Tsung-Yuan Chang, Bobby Nikjou
  • Publication number: 20020065056
    Abstract: An electronic tuning system includes an electronic tuner for adjusting the predetermined control voltage of a voltage controlled oscillator (VCO) to tune the local frequency signal to radio waves on an arbitrary channel in accordance with channel selection information. A booster circuit boosts a source voltage to generate a boosted voltage in order to ensure the predetermined control voltage. A non-volatile memory stores the channel selection information in response to a predetermined write voltage. The boosted voltage of the booster circuit is utilized as the predetermined write voltage.
    Type: Application
    Filed: November 26, 2001
    Publication date: May 30, 2002
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Yoh Takano, Fumihiro Sasaki
  • Patent number: 6181218
    Abstract: The invention provides a unique apparatus and method which varies the capacitance coupled to a circuit. In one embodiment, the variable capacitance comprises a unique variable capacitance array with multiple capacitance modules which can be selectively enabled. Each capacitance module has a capacitive value and a corresponding parasitic capacitance. The invention provides high linearity, low spread, improves the response to power fluctuations by maintaining a consistent relationship between the capacitive value and the parasitic capacitance in each capacitance module. For example, the invention can be used with devices to provide a linear variation of capacitance. In addition, the invention can be used to calibrate a wide range of devices.
    Type: Grant
    Filed: May 19, 1998
    Date of Patent: January 30, 2001
    Assignee: Conexant Systems, Inc.
    Inventors: Ricke W. Clark, Jorge A. Grilo, Bo Zhang
  • Patent number: RE40620
    Abstract: A monolithic AM transmitter is disclosed. An external antenna forms part of a resonance network so that the antenna resonance point is automatically tuned to the transmit frequency. This provides flexibility with no added cost to the transmitter. Additionally, components of the transmitter can be formed on a single monolithic integrated circuit.
    Type: Grant
    Filed: May 23, 2005
    Date of Patent: January 6, 2009
    Assignee: Micrel, Inc.
    Inventors: Joseph S. Elder, Mohammed D. Islam, Joseph T. Yestrebsky