Having Particular Biasing Means Patents (Class 330/285)
  • Patent number: 7932780
    Abstract: Voltage Enhancement Circuitry (VEC) for amplifiers, suitable of being implemented as an Integrated Circuit (IC), that comprises a VEC driver with a low output resistance (Rdson) while being in its inactive mode and a linearly increasing resistance that is changing linearly with the input control signal, while entering into its active mode, above a determined threshold; external contacts in the VEC, for connecting, whenever required, external feedback elements across the contacts; an external feedback loop connected to an input of the VEC driver, for sensing changes in the enhancement power; a threshold programming module, for externally programming and determining a threshold level for the input signal, above which enhancement is provided shaping the amplified video envelope pulse; an I-Boost module for sampling the amplitude of the video envelope input current and for amplifying the input current up to a pre-defined level; and a current controlled bias circuit for shifting, whenever required, the bias of the
    Type: Grant
    Filed: May 21, 2006
    Date of Patent: April 26, 2011
    Assignee: Paragon Communications Ltd.
    Inventor: Avner Elia
  • Patent number: 7932782
    Abstract: A biasing circuit is used to provide low distortion and high efficiency operation of a microwave power amplifier. The biasing circuit utilizes the nonlinear rectified current of a microwave diode or transistor for biasing the amplifying transistor self-adaptively. The biasing current not only reduces the DC bias power during low-power operation and increases self-adaptively during high-power operation, but also manipulates the intermodulation distortion minimum dynamically. Meanwhile, the biasing circuit distorts the input signals with positive gain and negative phase deviations. Therefore, the average power efficiency of the operation is enhanced, the linearity of the input-output characteristic is improved and the radiated level of adjacent channel power is suppressed.
    Type: Grant
    Filed: December 10, 2007
    Date of Patent: April 26, 2011
    Assignee: City University of Hong Kong
    Inventors: Kwok Wai Lau, Quan Xue, Wing Shing Chan, Chi Hou Chan
  • Patent number: 7930452
    Abstract: In one embodiment, an apparatus includes a driver and a receiver. The driver has an output, wherein the output of the driver has an associated output termination. In addition, the receiver has an input, wherein the input of the receiver has an associated input termination. An interface between the output of the driver and the input of the receiver operates according to a set of one or more timing parameters, wherein the input termination, the output termination, and the set of timing parameters correspond to a bandwidth for data transfer or frequency for data transfer across the interface between the output of the driver and the input of the receiver.
    Type: Grant
    Filed: June 5, 2007
    Date of Patent: April 19, 2011
    Assignee: Cisco Technology, Inc.
    Inventors: Judith Ying Priest, Ronnie Ka Lai Poon
  • Patent number: 7920836
    Abstract: A system for saturation detection, correction and recovery in a power amplifier includes a power amplifier, a closed power control loop configured to develop a power control signal (VPC), and power control circuitry configured to reduce the power control signal if the power amplifier is operating in a saturation mode.
    Type: Grant
    Filed: March 2, 2010
    Date of Patent: April 5, 2011
    Assignee: Skyworks Solutions, Inc.
    Inventors: Dmitriy Rozenblit, Tirdad Sowlati, Darioush Agahi
  • Patent number: 7907014
    Abstract: A system and method for dynamic adjustment of drain or collector voltage of a power amplifier (PA), including a PA having a voltage input, a temperature sensor measuring ambient temperature of the PA, and an adaptive PA control processor that dynamically changes the input voltage based on the ambient temperature, achieving a desired peak power when the system is subjected to high temperatures. In a further embodiment, a power sensor measures output power of the PA, and the control processor dynamically changes the voltage based on output power when the system serves a large cell in a mobile communication infrastructure employing high power. In a further embodiment, a multistage PA and method include amplifier stages having drain or collector voltage inputs, wherein a voltage applied to the inputs are set so as to be proportional to the peak power requirements of each stage, enhancing overall efficiency.
    Type: Grant
    Filed: May 30, 2010
    Date of Patent: March 15, 2011
    Assignee: Microelectronics Technology Inc.
    Inventors: Dung C. Nguyen, Soon Yoon, Ahmad Khanifar, Don C. Devendorf
  • Publication number: 20110050347
    Abstract: A method is disclosed wherein a power level indicating a level of transmission power from an amplifier is provided. An indication of at least one of channel, channel bandwidth, OOB spectral requirements, spectral mask requirements, EVM, modulation rate, and modulation type is also provided. A control signal for controlling one of a bias current provided to the amplifier and a matching circuit for matching an output port of at least a stage of the amplifier is generated, the control signal determined in dependence upon the power level and the at least an indication. Then the one of the bias current and the matching circuit is adjusted in accordance with the control signal.
    Type: Application
    Filed: August 27, 2009
    Publication date: March 3, 2011
    Applicant: SiGe Semiconductor Inc.
    Inventors: Alan Trainor, Darcy Poulin, Craig Christmas
  • Patent number: 7898335
    Abstract: There is provided an amplifier circuit includes: an amplifying transistor; a first transistor having a DC current amplification factor generally equal to the DC current amplification factor of the amplifying transistor and constituting a current mirror circuit in conjunction with the amplifying transistor; and a current source circuit being operable to supply a current to the first transistor and including a second transistor having opposite conductivity type to the conductivity type of the first transistor. The second transistor is operated in a saturation region at a power supply voltage lower than an operating voltage range so that the DC current amplification factor of the amplifying transistor can be detected.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: March 1, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Takayuki Teraguchi
  • Patent number: 7898339
    Abstract: An amplifier circuit with favorable linearity is provided. An amplifier of the present invention is provided with an amplifier MOS transistor, a diode-connected transistor block for negative feedback source impedance constituted by series-parallel connection of the limited number (including 0) of the diode-connected MOS transistors and connected to a source side of the amplifier MOS transistor, and a diode-connected transistor block for load constituted by series-parallel connection of the limited number of the diode-connected MOS transistors and connected to a drain side of the amplifier MOS transistor. A voltage gain is configured to be determined by a ratio of the sum of source impedance of the amplifier MOS transistor and the impedance of the diode-connected transistor block for negative feedback source impedance to the impedance of the diode-connected transistor block for load.
    Type: Grant
    Filed: May 14, 2009
    Date of Patent: March 1, 2011
    Assignees: Kabushiki Kaisha Nihon Micronics, NES Co., Ltd
    Inventors: Masato Ikeda, Tokio Miyashita
  • Patent number: 7893769
    Abstract: A power amplifier includes: a distortion compensating circuit that causes a bias circuit to have an output impedance so that a subsequent block bipolar transistor for signal amplification-use has a maximized saturated output power; and a distortion compensating circuit that causes a bias circuit to have an output impedance so that a distortion of an output power of the power amplifier 1 with respect to an input power is canceled by a distortion characteristic of an output power with respect to an input power of the subsequent block bipolar transistor for signal amplification-use which has a maximized saturated output power and a distortion characteristic of an output power with respect to an input power of the preceding block bipolar transistor for signal amplification-use. This makes it possible to provide a power amplifier that allows reduction in saturated output power brought by realization of a highly efficient low-distortion power amplifier.
    Type: Grant
    Filed: June 12, 2009
    Date of Patent: February 22, 2011
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Hiroyuki Asano
  • Patent number: 7893771
    Abstract: A power amplifier includes a bipolar transistor and a self-adaptive bias network situated between an RF input and the base of the bipolar transistor. The self-adaptive bias network suppresses the low frequency even-order intermodulation components. The self-adaptive bias network stabilizes a DC bias voltage to provide a substantially constant base-emitter voltage and provides an increased DC base current with increased input power when the power amplifier is operating within the nonlinear region.
    Type: Grant
    Filed: January 5, 2007
    Date of Patent: February 22, 2011
    Assignee: City University of Hong Kong
    Inventors: Kwok Wai Lau, Quan Xue
  • Patent number: 7889000
    Abstract: Aspects of a method and system for polar modulating OFDM signals with discontinuous phase may include amplifying a normalized OFDM signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain and an amplitude offset gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain adaptively and/or dynamically. The setting of the coarse amplitude gain and/or the amplitude offset gain may be adjusted dynamically and/or adaptively via an amplitude control.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: February 15, 2011
    Assignee: Broadcom Corporation
    Inventor: Ahmadreza Rofougaran
  • Publication number: 20110018637
    Abstract: A radiofrequency signal power amplification circuit may include a signal input for receiving the radiofrequency signal, an amplification stage coupled to the signal input and having at least one power transistor, a biasing stage for delivering a bias voltage to the amplification stage, and a processing stage. The processing stage may include a processing input coupled to the signal input, a processing output for delivering a bias current modulated at least in amplitude to the biasing stage, and an amplitude modulator coupled between the processing input and the processing output and configured to determine an envelope signal representative of the envelope of the radiofrequency signal, for modulating the amplitude of the envelope signal based on a variable voltage setpoint and for generating the amplitude-modulated bias current based on the modulated envelope signal.
    Type: Application
    Filed: July 22, 2010
    Publication date: January 27, 2011
    Applicant: STMicroelectronics SA
    Inventors: Didier Belot, Laurent Leyssenne, Eric Kerherve, Yann Deval
  • Patent number: 7876157
    Abstract: A power amplifier bias circuit having a controllable current profile includes a first transistor device configured as a switch, and configured to receive a non-regulated system voltage, and a plurality of resistors configured to provide a current and configured to determine an amount of a bias current that flows through a second transistor device, where the second transistor device is part of a current mirror comprising a third transistor device and the amount of bias current flowing through the second transistor device determines a power output of the third transistor device.
    Type: Grant
    Filed: August 4, 2009
    Date of Patent: January 25, 2011
    Assignee: Skyworks Solutions, Inc.
    Inventors: Li-hung Kang, Younkyu Chung
  • Patent number: 7876156
    Abstract: An RF power amplifier has a final-stage amplifier stage which generates an RF transmit output signal, a signal detector which detects an RF transmit output level, a first detector, a second detector and a control circuit. The final-stage amplifier stage includes a transistor and a load element and performs saturation type nonlinear amplification and non-saturation type linear amplification. The first detector and the control circuit maintain the RF transmit output signal approximately constant with respect to a variation in load at an antenna at the saturation type nonlinear amplification. The second detector and the control circuit reduce an increase in the output voltage of the final stage transistor with respect to an overload state of the antenna at the non-saturation type linear amplification.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: January 25, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Satoshi Tanaka, Tomonori Tanoue
  • Patent number: 7868696
    Abstract: Aspects of a method and system for a highly efficient power amplifier (PA) utilizing dynamic biasing and predistortion are presented. Aspects of the system may include a processor that enables computation of a value of a variable bias component of a bias current based on a bias slope value and an amplitude of an envelope input signal. The processor may enable computation of a value of the bias current based on the selected constant bias current component value and the variable bias current component value. A PA may enable generation of an output signal in response to a generated baseband signal by utilizing the bias current to amplify an amplifier input signal. The bias current may be generated based on the envelope input signal. A feedback signal may be generated based on the output signal, which may be used to predistort a subsequent baseband signal.
    Type: Grant
    Filed: March 15, 2010
    Date of Patent: January 11, 2011
    Assignee: Broadcom Corporation
    Inventors: Arya Behzad, Ali Afashi, Vikram Magoon
  • Patent number: 7863983
    Abstract: A power amplifier subsystem that includes a first stage amplifier and a second stage amplifier. A first bias circuit is coupled to the first stage amplifier, and the first bias circuit has a variable impedance that increases with radio frequency (RF) power. A second bias circuit is coupled to the second stage amplifier, and the second bias circuit has impedance relatively fixed with respect to radio frequency (RF) power. According to an embodiment of the invention, the first bias circuit comprises a transistor having a collector current that increases as radio frequency (RF) power increases. The second bias circuit can have a relatively fixed impedance. A method of designing an amplifier subsystem, where transistor size and resistor values are selected to obtain the desired bias and linearity characteristics, or transistor size and resistor values are selected to operate within a selected range, and amplifier performance is adjusted by changing the bias control voltage.
    Type: Grant
    Filed: May 19, 2004
    Date of Patent: January 4, 2011
    Assignee: Epic Communications, Inc.
    Inventors: Cindy Yuen, Kirk Laursen, Duc Chu
  • Patent number: 7863984
    Abstract: Disclosed is an apparatus and method for operating a microwave amplifier with improved efficiency and reduced harmonic emissions. The disclosed amplifier includes a variable rail voltage supply and a variable input drive stage. A controller continually monitors the amplifier output and adjusts the rail voltage and input drive signal to achieve high efficiency and low harmonic emissions. The amplifier may include a dynamic bias controller configured to operate the gain elements outside the linear region. Efficiencies of over 70% may be achieved by the disclosed amplifier.
    Type: Grant
    Filed: July 17, 2009
    Date of Patent: January 4, 2011
    Assignee: Vivant Medical, Inc.
    Inventor: Robert J. Behnke
  • Patent number: 7859335
    Abstract: Aspects of a method and system for polar modulating QAM signals with discontinuous phase may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain and an amplitude offset gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain. The setting of the coarse amplitude gain and/or said amplitude offset gain may be adjusted dynamically and/or adaptively. The signal may be generated by phase-modulation of a radio-frequency carrier. The combined gain of the plurality of amplifiers may be controlled based on a desired amplitude modulation. The plurality of amplifiers may be integrated within an integrated circuit (IC) or chip.
    Type: Grant
    Filed: September 1, 2009
    Date of Patent: December 28, 2010
    Assignee: Broadcom Corporation
    Inventor: Ahmadreza Rofougaran
  • Patent number: 7860467
    Abstract: A circuit may be provided. The circuit may be a component of a dual mode transmitter such as a transmitter from the 802.11x family. The circuit may comprise an amplifier configured to provide amplification of a signal for transmission in either a first transmission mode or a second transmission mode, using power supplied from a power supply, the amplifier including at least one cascode transistor in series with at least one amplifying transistor. The circuit may further comprise a power controller configured to define an operating characteristic of the at least one cascode transistor, and thereby designate an amount of the power from the power supply that is used by the amplifier during the amplification, based on whether the amplifier is to be operated in the first transmission mode or the second transmission mode.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: December 28, 2010
    Assignee: Broadcom Corporation
    Inventor: Meng-An Pan
  • Patent number: 7855601
    Abstract: A semiconductor device including: a gain control circuit; a first circuit which is controlled a gain to be constant by the gain control circuit; and a bias circuit connected to the first circuit, wherein the first circuit including a first transistor; and a load resistance, an amplification factor or an attenuation factor of the first circuit is proportionate to a product of a transconductance of the first transistor and a resistance value of the load resistance, and a voltage applied to the load resistance is set as an output of the semiconductor device, the bias circuit generates and outputs a differential current of a current that is proportionate to a drain current flowing into the first transistor and a current that is inversely proportionate to the load resistance value, and an output of the bias circuit is connected to an output node of the first circuit.
    Type: Grant
    Filed: March 16, 2009
    Date of Patent: December 21, 2010
    Assignee: Fujitsu Limited
    Inventor: Kazuaki Oishi
  • Publication number: 20100315166
    Abstract: There is provided a variable gain circuit system which is inductorless and capable of achieving a high gain and a wide band by elements for achieving variable gain to prevent decreasing a gain or deteriorating the band. The variable gain circuit includes: transistors; a resistor connected as a load of each transistor; a voltage source applying a bias voltage to each gate of the transistors; a switch selectively connecting the voltage source or a ground potential to each gate of the transistors in accordance with gain setting; and a current source connected to a common input. A drain of each transistor is connected to an input of a circuit in a subsequent stage.
    Type: Application
    Filed: June 9, 2010
    Publication date: December 16, 2010
    Applicant: Hitachi, Ltd.
    Inventors: Takehito KAMIMURA, Norio Chujo
  • Patent number: 7852153
    Abstract: A post-distortion method for cascading amplifier stages in a two-stage microwave power amplifier and a dynamic biasing method using back-end processing for correcting nonlinearity in the power amplifier output. A first or driver stage biased in a near-A region with low distortion is cascaded with a second or power stage biased in a near-C region with high efficiency. The amplitude and phase responses of the two stages compensate another to yield a more linear overall gain for the overall power amplifier. The dynamic biasing scheme modulates the source to drain voltages of the transistors used in the amplifier stages based on the harmonics in amplifier output in order to minimize the harmonics and correct non-linearity in the output.
    Type: Grant
    Filed: October 24, 2008
    Date of Patent: December 14, 2010
    Assignee: HRL Laboratories, LLC
    Inventors: Grant Andrew Ellis, Miroslav Micovic, Keh-Chung Wang, JeongSun Moon
  • Patent number: 7843267
    Abstract: A method for compensating a power amplifier based on operational-based changes begins by measuring one of a plurality of operational parameters of the power amplifier to produce a measured operational parameter. The method continues by comparing the measured operational parameter with a corresponding one of a plurality of desired operational parameter settings. The method continues by, when the comparing of the measured operational parameter with the corresponding one of a plurality of desired operational parameter settings is unfavorable, determining a difference between the measured operational parameter and the corresponding one of a plurality of desired operational parameter settings. The method continues by calibrating the one of the plurality of operational settings based on the difference.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: November 30, 2010
    Assignee: Broadcom Corporation
    Inventor: Seema B. Anand
  • Patent number: 7843271
    Abstract: An audio amplifier includes an output stage for generating an output stage voltage in response to an input signal and an output stage quiescent current. A controlled current source controls the output stage quiescent current in response to a quiescent current signal during a start-up cycle.
    Type: Grant
    Filed: March 27, 2006
    Date of Patent: November 30, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Charles Eric Seaberg
  • Patent number: 7839216
    Abstract: Designs and techniques associated with power amplifiers for amplifying RF signals to provide variable power amplification and improved linearity in various RF amplification circuits, including power amplifiers operated under the power back-off conditions.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: November 23, 2010
    Assignee: Rayspan Corporation
    Inventors: Raul Alidio, Alexandre Dupuy, Ajay Gummalla, Woo Yong Lee, Maha Achour
  • Patent number: 7834701
    Abstract: A plurality of analog signals are input to input terminals of an analog signal processing circuit ANA2 via respective capacitors C. In a bias circuit Bias for supplying a bias voltage such as a signal ground of the analog signals to the analog signal processing circuit ANA2, in an operational amplifier OpAS, a bias voltage VIr is input from a non-inverting input VIP of a built-in differentiate amplifier circuit, an output terminal of the built-in output amplifier circuit OA1 is connected to an inverting input terminal VIM of the differentiate amplifier circuit DA, and thereby a voltage follower is obtained. Furthermore, a plurality of output amplifier circuits OA2 through OAn are provided so that input terminals thereof are connected to output terminals of the differential amplifier circuit DA, and the output terminals are connected to input terminals IN1 through INn of the analog signal processing circuit ANA2.
    Type: Grant
    Filed: May 28, 2008
    Date of Patent: November 16, 2010
    Assignee: Panasonic Corporation
    Inventors: Tsuyoshi Matsushita, Koji Oka, Junichi Naka
  • Patent number: 7834687
    Abstract: Aspects of a method and system for polar modulation with discontinuous phase for RF Transmitters with power control may include performing by one or more circuits comprising a plurality of amplifiers, configuring one or more of the plurality of amplifiers to provide a coarse amplitude gain and a power level gain. One or more remaining ones of the plurality of amplifiers may be configured to provide an amplitude offset gain, and a signal may be amplified utilizing a combined gain provided by the one or more of the plurality of amplifiers and by the one or more remaining ones of the plurality of amplifiers. The signal may comprise modulated RF signal, and/or a phase modulated RF signal. An RF carrier signal may be modulated to generate the signal.
    Type: Grant
    Filed: May 15, 2009
    Date of Patent: November 16, 2010
    Assignee: Broadcom Corp.
    Inventor: Ahmadreza Rofougaran
  • Patent number: 7830208
    Abstract: A common-base amplifier for a bipolar junction transistor or a heterojunction bipolar transistor employs an active current source output biasing to provide for improved power output in a power saturation region providing increased power for a given transistor area such as may be advantageous in mobile radio transmitters or the like.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: November 9, 2010
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Zhenqiang Ma, Guogong Wang, Guoxuan Qin
  • Patent number: 7825730
    Abstract: A bias circuit for the wireless transceiver is disclosed, which can be used for modulating the gain of the amplifier. The bias circuit comprises a first stage bias unit for receiving a constant current, a control voltage, and a first reference voltage and outputting a first outputting current, wherein the control voltage is used for controlling the value of the first outputting current, and further, the first outputting current can be increased or decreased by representing as an analog form, thus, the gain of the amplifier can be modulated according to the first outputting current, and the modulation of the gain can be represented as an analog form, such that the transient response occurred while the gain is modulated can be reduced.
    Type: Grant
    Filed: July 3, 2008
    Date of Patent: November 2, 2010
    Assignee: Airoha Technology Corp.
    Inventors: John-San Yang, Shu-Fen Wei
  • Patent number: 7808322
    Abstract: A system comprises a variable gain amplifier (VGA) that amplifies an input signal with a gain that is based on a gain control signal. A power amplifier receives an output of the VGA. Memory switches between at least two of N output power settings each including a predetermined reference value and a predetermined gain offset value. The memory substantially concurrently changes from the predetermined reference value and the predetermined gain offset value of a prior one of the N output power settings to the predetermined reference value and the predetermined gain offset value of a current one of the N output power settings, where N is an integer greater than one. A gain control adjuster adjusts the gain control signal based on an output of the power amplifier and the predetermined reference value and gain offset value of the current one of the N output power settings.
    Type: Grant
    Filed: January 23, 2007
    Date of Patent: October 5, 2010
    Assignee: Marvell International Ltd.
    Inventors: Sang Won Son, King Chun Tsai, Yuan-Ju Chao, Lawrence Tse
  • Patent number: 7787851
    Abstract: The invention specifies a circuit arrangement with a radio-frequency mixer (4) in which a plurality of preamplifiers (1, 2, 3) in a receiver have a common output node (6). This node is connected to a common, broadband radio-frequency mixer (4) via common coupling capacitances (41, 42). Switching means (17, 18; 27, 28; 37, 38) can be used to connect and disconnect the preamplifiers (1 to 3), which can be associated with various frequency bands, independently of one another. The present principle can be applied in multiband receivers in mobile radio and allows integration using little chip area with good radio-frequency characteristics.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: August 31, 2010
    Assignee: Infineon Technologies AG
    Inventor: Axel Schmidt
  • Patent number: 7786805
    Abstract: A power amplifier module comprises a power amplifier circuit having an output power level controlled by a power supply voltage. A power supply transistor controls the power supply to the power amplifier circuit from a drive signal which is received from a drive circuit. The drive circuit generates the drive signal in response to a power level input signal, which specifically may correspond to a power ramping for a GSM cellular communication system. The power amplifier module furthermore comprises a detection circuit which determines an operating characteristic of the power supply transistor. The operating characteristic is preferably a saturation characteristic. A control circuit controls the drive signal in response to the operating characteristic. The control circuit preferably controls the drive signal such that the power supply transistor does not enter the linear region for a Field Effect Transistor and the saturated region for a bipolar transistor.
    Type: Grant
    Filed: December 13, 2004
    Date of Patent: August 31, 2010
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Gerhard Trauth, Ludovic Oddoart, Jacques Trichet, Vincent Vanhuffel
  • Patent number: 7774019
    Abstract: A transconductor input circuit for a down converting quadrature mixer stage of a direct-conversion receiver comprises a pair of common-gate input transistors whose source electrodes are coupled to a differential radio frequency (RF) input signal outputted from an interstage RF filter. The transconductor circuit further comprises a pair of equally-sized biasing transistors for biasing the pair of common-gate input transistors. Source electrodes of the biasing transistors are coupled to the source electrodes of the transistors to sense the differential radio frequency input signal for canceling intermodulation distortion.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: August 10, 2010
    Assignee: Nokia Corporation
    Inventors: Pete Sivonen, Ari Vilander
  • Patent number: 7768345
    Abstract: The present invention provides compensation for distortions in a multi-stage amplifier having a gain expansion characteristic. The present invention also provides an approach for using an amplification stage biased in a state close to B-class, which exhibits high power with added efficiency at low output, in order to have a gain expansion characteristic in all stages of a multi-stage amplifier. The amplifier of the present invention has a gain expansion characteristic which presents an increase in gain in response to an increase in input power or output power in a certain range of the input power or the output power.
    Type: Grant
    Filed: December 27, 2004
    Date of Patent: August 3, 2010
    Assignee: NEC Corporation
    Inventor: Yuuichi Aoki
  • Patent number: 7768353
    Abstract: Embodiments of the invention may provide for enhancement systems and methods for a power amplifier output control system. In an example embodiment, driver amplifier control may be provided in conjunction with power amplifier control to improve the power efficiency and/or dynamic range of the transmitter system. Furthermore, control over the driver amplifier may allow for relaxed power control slope, which may lessens the burden of digital to analog converters (DACs) in transmitter systems such as cellular transmitter systems. Also, systems and methods in accordance with example embodiments of the invention may provide a less sensitive solution to operational environment variations such as temperature, battery power voltage and implementation IC process.
    Type: Grant
    Filed: June 13, 2008
    Date of Patent: August 3, 2010
    Assignee: Samsung Electro-Mechanics Company, Ltd.
    Inventors: Jaejoon Chang, Ki Seok Yang, Kyu Hwan An, Wangmyong Woo, Chang-Ho Lee, Younsuk Kim, Hyogun Bae, Kijoong Kim, Shinichi Iizuka
  • Patent number: 7760024
    Abstract: A system and method for increasing accuracy of transmitter power detection over a larger range of output power levels wherein a diode detector is followed by a series cascade of 2 op amps. The first op amp functions as a differential/buffer amplifier, which improves temperature performance. The second op amp has two selectable gain factors. The output of the second op amp is routed to the ADC. A single control line is connected to a controllable switching device that configures the second op amp for high gain or low gain.
    Type: Grant
    Filed: October 7, 2005
    Date of Patent: July 20, 2010
    Assignee: Cisco Technology, Inc
    Inventors: Petros Giatis, Gerald B. Johnson, Franklin D. Simon, Jr., Corey Metsker
  • Patent number: 7746168
    Abstract: A bias circuit of a resistance load differential amplifier comprises a first differential pair and a control unit for controlling a tail current of the first differential pair, and making an output current of the first differential pair being in inverse proportion to a load resistance in the resistance load differential amplifier when applying a constant potential difference to an input of the first differential pair. The control unit further controls a tail current of a second differential pair constituting the resistance load differential amplifier, and makes the tail current of the second differential pair being in direct proportion to the tail current of the first differential pair.
    Type: Grant
    Filed: August 17, 2006
    Date of Patent: June 29, 2010
    Assignee: Fujitsu Semiconductor Limited
    Inventor: Kazuaki Oishi
  • Publication number: 20100156539
    Abstract: A power amplifier system with power control function provides accurate and efficient power control by controlling a bias voltage and a bias current of the power amplifier at the same time.
    Type: Application
    Filed: November 13, 2009
    Publication date: June 24, 2010
    Applicant: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Sang Hoon Ha, Sang Hee Kim, Joong Jin Nam, Ki Joong Kim, Jae Hyouck Choi, Shinichi Ilzuka, Youn Suk Kim
  • Patent number: 7741912
    Abstract: The present invention relates to amplifier bias circuitry, which provides a direct current (DC) bias to a radio frequency (RF) amplifier. The amplifier bias circuitry includes a control loop having a control loop bandwidth, and an output impedance associated with providing the DC bias to the RF amplifier. The amplifier bias circuitry may vary the DC bias, the output impedance, the control loop bandwidth, or any combination thereof, to meet wireless communications requirements. For example, in a multi-mode radio, low output impedance may be needed to meet linearity requirements of the RF amplifier associated with wireless communications protocols in one mode of the multi-modes; however, some low output impedance designs may reduce the control loop bandwidth below that needed to meet modulation requirements associated with wireless communications protocols in another mode of the multi-modes.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: June 22, 2010
    Assignee: RF Micro Devices, Inc.
    Inventor: Praveen V. Nadimpalli
  • Patent number: 7719354
    Abstract: A dynamic biasing system (“DBS”) for dynamically biasing an amplifier with an adjusted bias signal is shown. The DBS may include a first biasing circuit that produces a bias signal and a second biasing circuit in signal communication with both the first biasing circuit and the amplifier, wherein the second biasing circuit compares the bias signal to a predetermined threshold and in response produces the adjusted bias signal.
    Type: Grant
    Filed: July 1, 2008
    Date of Patent: May 18, 2010
    Assignee: Skyworks Solutions, Inc.
    Inventor: Nicolas Constantin
  • Publication number: 20100109778
    Abstract: A broad-band linear amplifier circuit includes a driver amplifier to produce a first amplified radio frequency (RF) signal in a first single RF band in response to a first input RF signal and to produce a second amplified RF signal in a second single RF band in response to a second input RF signal. The first single RF band and the second single RF band reside in a broad band that has a bandwidth more than two times a bandwidth of the first single RF band or the second single RF band. A sensing circuit can sense a power, a gain, or a phase of the first output RF signal and the second output RF signal, and to produce a sensing signal. A gain control circuit controls gain variation of the driver amplifier in response to the sensing signal.
    Type: Application
    Filed: October 31, 2008
    Publication date: May 6, 2010
    Inventors: Ikuroh Ichitsubo, Brian Michael Wang
  • Publication number: 20100102887
    Abstract: An electronic component for high frequency power amplification realizes an improvement in switching spectrum characteristics. The gain of an amplifying NMOS transistor is controlled by a bias voltage on which a bias control voltage is reflected. Further, a threshold voltage compensator compensates for a variation in threshold voltage with variations in the manufacture of the amplifying NMOS transistor. The threshold voltage compensator includes an NMOS transistor formed in the same process specification as the amplifying NMOS transistor and converts a variation in current flowing through the NMOS transistor depending on the variation in the threshold voltage of the amplifying NMOS transistor to its corresponding voltage by a resistor to compensate for the bias voltage. It is thus possible to reduce variations in so-called precharge level brought to fixed output power in a region (0 dBm or less, for example) low in output power.
    Type: Application
    Filed: September 24, 2009
    Publication date: April 29, 2010
    Applicant: RENESAS TECHNOLOGY CORP.
    Inventors: Kyoichi TAKAHASHI, Kazuhiro KOSHIO, Satoshi TANAKA
  • Patent number: 7705680
    Abstract: In a gain switching LNA including a first transistor, a first transistor group (for example, second to ninth transistors) and a second transistor group (for example, tenth to seventeenth transistors), a first resistor connected between an emitter of the tenth transistor and a collector of the first transistor and a second resistor connected to emitters of eleventh to seventeenth transistors and the collector of the first transistor and having a resistance one seventh as high as that of the first resistor are provided. In a high-gain mode, since isolation of the tenth to seventeenth transistors which are turned OFF and the first and second to ninth transistors is secured by the first resistor and the second resistor, there is no deterioration in the noise factor.
    Type: Grant
    Filed: April 14, 2008
    Date of Patent: April 27, 2010
    Assignee: Renesas Technology Corp.
    Inventors: Yutaka Igarashi, Akio Yamamoto
  • Patent number: 7706760
    Abstract: A system for saturation detection, correction and recovery in a power amplifier includes a power amplifier, a closed power control loop configured to develop a power control signal (VPC), and power control circuitry configured to reduce the power control signal if the power amplifier is operating in a saturation mode.
    Type: Grant
    Filed: May 10, 2006
    Date of Patent: April 27, 2010
    Assignee: Skyworks Solutions, Inc.
    Inventors: Dmitriy Rozenblit, Tirdad Sowlati, Darioush Agahi
  • Publication number: 20100085119
    Abstract: In one embodiment, a method includes generating a current that is proportional to a mobility and an oxide capacitance of a tracking device and independent of a threshold voltage variation of the tracking device, generating a voltage from the current, and providing the voltage as at least part of a bias voltage for another device. In one embodiment, this other device may be a compensation circuit coupled to a main device to compensate for capacitance non-linearity of the main device.
    Type: Application
    Filed: October 14, 2009
    Publication date: April 8, 2010
    Inventors: Anil Samavedam, David E. Bockelman, Vishnu Srinivasan
  • Patent number: 7683711
    Abstract: A voltage regulator, comprising an analog amplifier, a noise filter and a signal compensator, is disclosed. The noise filter for receives a first signal containing alternating current (AC) noise in which the noise filter substantially filters the AC noise from the first signal to thereby produce a second signal. The voltage regulator regulates the second signal to thereby generate a third signal therefrom. The third signal is substantially noise-free and is provided as a biasing voltage to the analog amplifier. The first signal is further provided to for amplification by the analog amplifier based on amplification characteristics of the analog amplifier and the amplification characteristics of the analog amplifier is determined by the biasing voltage provided to the analog amplifier.
    Type: Grant
    Filed: November 29, 2007
    Date of Patent: March 23, 2010
    Inventor: Lup Yoong Kam
  • Patent number: 7679449
    Abstract: Aspects of a method and system for a highly efficient power amplifier (PA) utilizing dynamic biasing and predistortion are presented. Aspects of the system may include a processor that enables computation of a value of a variable bias component of a bias current based on a bias slope value and an amplitude of an envelope input signal. The processor may enable computation of a value of the bias current based on the selected constant bias current component value and the variable bias current component value. A PA may enable generation of an output signal in response to a generated baseband signal by utilizing the bias current to amplify an amplifier input signal. The bias current may be generated based on the envelope input signal. A feedback signal may be generated based on the output signal, which may be used to predistort a subsequent baseband signal.
    Type: Grant
    Filed: August 14, 2008
    Date of Patent: March 16, 2010
    Assignee: Broadcom Corporation
    Inventors: Arya Behzad, Ali Afashi, Vikram Magoon
  • Patent number: 7679448
    Abstract: A biasing circuit and method for minimizing distortion in a MOS transistor. A first CW source provides a first CW signal at the input of a replica transistor to obtain an output signal at the output of the replica transistor. The output signal is mixed with another CW signal having a frequency equal to N times that of the first CW signal, N being an integer greater than one, to obtain a mixed signal having a DC component with an intensity proportional to the Nth-order distortion present in the output signal. A bias voltage to minimize this distortion is then applied to the input of the original transistor on which the replica transistor is based, the bias voltage determined in accordance with the intensity of the DC component.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: March 16, 2010
    Assignee: PMC-Sierra, Inc.
    Inventors: Matthew W. McAdam, Francis Beaudoin
  • Patent number: 7675361
    Abstract: A class-D amplifier and a method of generating a multi-level output signal thereof are provided. The class-D amplifier includes a controlling logic circuit and an output module. The controlling logic circuit analyzes the amplitude of an input signal to generate a voltage modifying signal. A power supply provides a voltage according to the voltage modifying signal. The controlling logic circuit generates controlling signals according to the input signal. The output module generates an output signal to drive a load according to the voltage and the controlling signals. In other words, the resolution of the amplitude of the output signal is increased by modifying the voltage, and a signal to noise ratio is then increased.
    Type: Grant
    Filed: February 4, 2008
    Date of Patent: March 9, 2010
    Assignee: ITE Tech. Inc.
    Inventors: Lee-Chun Guo, Ming-Hsun Sung
  • Publication number: 20100052789
    Abstract: This disclosure relates systems and methods for a power amplifier with output power control. The power amplifier can include multiple stages of amplification. An RF signal is fed to the power amplifier with output control that amplifies the power of the RF signal to meet operational requirements. A first stage of the power amplifier controls the output power via voltage regulation. An isolating device is introduced in the transmission path of the RF signal between the first stage and the following stages of the power amplifier. The isolating device ensures that the load impedance of the first stage remains fixed at a constant value.
    Type: Application
    Filed: September 3, 2008
    Publication date: March 4, 2010
    Applicant: Infineon Technologies AG
    Inventors: Winfried Bakalski, Markus Zannoth