Signal Feedback Patents (Class 330/75)
  • Patent number: 9042487
    Abstract: Apparatus and methods disclosed herein perform gain, clipping, and phase compensation in the presence of I/Q mismatch in quadrature RF receivers. Gain and phase mismatch are exacerbated by differences in clipping between I & Q signals in low resolution ADCs. Signals in the stronger channel arm are clipped differentially more than weaker signals in the other channel arm. Embodiments herein perform clipping operations during iterations of gain mismatch calculations in order to balance clipping between the I and Q channel arms. Gain compensation coefficients are iteratively converged, clipping levels are established, and data flowing through the network is gain and clipping compensated. A compensation phase angle and phase compensation coefficients are then determined from gain and clipping compensated sample data. The resulting phase compensation coefficients are applied to the gain and clipping corrected receiver data to yield a gain, clipping, and phase compensated data stream.
    Type: Grant
    Filed: August 13, 2012
    Date of Patent: May 26, 2015
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Ganesan Raghu, Bijoy Bhukania, Jaiganesh Balakrishnan
  • Patent number: 9035700
    Abstract: A variable gain amplifier (100) includes a transistor (110), an FB impedance section (120), a source impedance section (130), a drain impedance section (140), a gain controller (150), and a frequency characteristic controller (160). The gain controller (150) varies impedance of one of the FB impedance section (140), the source impedance section (130), and the drain impedance section (140), and outputs a gain control signal. The frequency characteristic controller (160) varies the impedance of different impedance section, based on the gain control signal.
    Type: Grant
    Filed: December 5, 2012
    Date of Patent: May 19, 2015
    Assignee: PANASONIC CORPORATION
    Inventor: Ryo Kitamura
  • Patent number: 9024690
    Abstract: An amplification unit is provided. The amplification unit, comprises a first amplifier, a second amplifier, a first sensor, a first predistortion component, and a signal combiner. The first amplifier amplifies a first signal to produce a second signal. The first sensor produces a third signal based on the second signal. The second amplifier turns on and to amplifies a fourth signal to produce a fifth signal when the amplitude of the fourth signal exceeds a threshold amplitude and turns off when the amplitude of the fourth signal is less than the threshold amplitude. The first predistortion component produces the first signal based on a first input signal, based on the third signal, and based on an on-off state of the second amplifier. The signal combiner produces an output of the amplification unit based on the second signal and the fifth signal.
    Type: Grant
    Filed: July 11, 2011
    Date of Patent: May 5, 2015
    Assignee: RPX Clearinghouse LLC
    Inventors: Scott Widdowson, Gregory Bowles, Arthur Fuller
  • Publication number: 20150091642
    Abstract: In an amplifier, a first stage receives a differential input voltage, which is formed by first and second input voltages, and outputs a first differential current in response thereto on first and second lines having respective first and second line voltages. A second stage receives the first and second line voltages and outputs a second differential current in response thereto on third and fourth lines having respective third and fourth line voltages. A transformer includes first and second coils. A first terminal of the first coil is coupled through a first resistor to the first line. A second terminal of the first coil is coupled through a second resistor to the second line. A first terminal of the second coil is coupled through a third resistor to the third line. A second terminal of the second coil is coupled through a fourth resistor to the fourth line.
    Type: Application
    Filed: October 30, 2013
    Publication date: April 2, 2015
    Applicant: Texas Instruments Incorporated
    Inventors: Swaminathan Sankaran, Bradley Allen Kramer, Hassan Ali, Nirmal C. Warke
  • Patent number: 8918069
    Abstract: A radio frequency transmitter comprising a modem which receives one or more input data signals and an adaptive predistortion signal and provides a baseband in-phase signal and a baseband quadrature signal. The transmitter may comprise a power amplifier module which receives the in-phase and quadrature phase signals and provides a radio frequency output signal. A predistortion module receives the radio frequency signal, downconverts the radio frequency signal to an intermediate frequency signal, and downconverts the intermediate frequency signal to a baseband feedback signal. The transmitter samples the feedback signal and provides an adaptive predistortion signal to the modem.
    Type: Grant
    Filed: January 10, 2012
    Date of Patent: December 23, 2014
    Assignee: Aviat U.S., Inc.
    Inventors: Ying Shen, James Laudolff, Travis Mashburn, Todd Nichols, David C. Schafer, Thanh H. Nguyen
  • Publication number: 20140285260
    Abstract: An output buffer circuit of a source driver includes an operational amplifier, having a first terminal as an output of the operational amplifier, and an output control unit, coupled between the output terminal of the operational amplifier and a second terminal for driving a load, to generate a variable impedance of a signal output path between the first terminal and the second terminal, wherein when the operational amplifier charges or discharges the second terminal to reach a predetermined level, the output control unit change a value of the variable impedance of the signal output path.
    Type: Application
    Filed: June 3, 2014
    Publication date: September 25, 2014
    Applicant: NOVATEK Microelectronics Corp.
    Inventors: Xie-Ren Hsu, Ji-Ting Chen, Yao-Hung Kuo
  • Patent number: 8841972
    Abstract: An electronic device, a fiber-optic communication system comprising the electronic device and a method of operating the electronic device are provided. The electronic device comprises a transimpedance-type amplifier having a transimpedance stage comprising an amplifier which is coupled in series with an input node. A feedback resistor is coupled in series between an output node of the amplifier and an inverting input node of the amplifier to provide a virtual ground node which is coupled to the input node, the inverting input node of the amplifier and to the feedback resistor. A current source is coupled to the virtual ground node so as to compensate for an offset current in an input signal which is coupled to the input node of the electronic device. Further, the electronic device comprises a control stage which is configured to control the current source as a function of a current through the feedback transistor.
    Type: Grant
    Filed: October 19, 2012
    Date of Patent: September 23, 2014
    Assignee: Texas Instruments Deutschland GmbH
    Inventor: Gerd Schuppener
  • Publication number: 20140266423
    Abstract: An RF PA system that generates its own local characterization information. The RF PA system includes a PA to generate a RF output signal from a RF input signal, the PA powered by a supply voltage. A characterization block generates characterization information corresponding to a relationship between the supply voltage and performance (e.g., gain, power efficiency, distortion, receive band noise) of the RF PA system for a plurality of levels of one or more operating conditions (e.g., temperature, operating frequency, modulation format, antennae mismatch, etc.) of the RF PA system. An amplitude estimator block estimates an amplitude of the RF input signal. A supply control block generates a supply voltage control signal for controlling the supply voltage based on the characterization information and the amplitude of the RF input signal.
    Type: Application
    Filed: March 13, 2014
    Publication date: September 18, 2014
    Applicant: Quantance, Inc.
    Inventors: Serge Francois Drogi, Vikas Vinayak
  • Publication number: 20140266422
    Abstract: An amplifying circuit comprises an analog amplifying circuit having an analog input for receiving an analog input signal to be amplified and an analog output for outputting an amplified analog signal, wherein the amplifying circuit comprises an implementation of a complex transfer function. A feedback circuit has a feedback circuit input and a feedback circuit output, wherein the feedback circuit comprises an implementation of an inverse transfer function that is an estimation of an inverse of at least a DC component of the complex transfer function of the analog amplifying circuit. The feedback circuit input is arranged for receiving a signal that is based on the amplified analog signal of the analog amplifying circuit. The analog circuit is arranged for receiving a bias signal that is based on the feedback circuit output.
    Type: Application
    Filed: August 2, 2013
    Publication date: September 18, 2014
    Applicant: Dialog Semiconductor B.V.
    Inventors: Soren Rievers, Jan Geert Prummel
  • Publication number: 20140213196
    Abstract: An envelope tracking system and a method for adjusting a nonlinear transfer function of an envelope tracking power supply for a power amplifier are provided. An output signal of the power amplifier is provided to a feedback receiver for determining an actual performance of the envelope tracking power amplifier. An assumed performance of the envelope tracking power amplifier is determined by evaluating the nonlinear transfer function at a value defined by an input signal for a transmitter including the power amplifier. A difference between the assumed performance and the actual performance provides a correctional value for the nonlinear transfer function.
    Type: Application
    Filed: January 31, 2013
    Publication date: July 31, 2014
    Inventors: Andreas Langer, Gunther Kraut, Berndt Pilgram
  • Publication number: 20140203868
    Abstract: A parallel amplifier and a parallel amplifier power supply are disclosed. The parallel amplifier power supply provides a parallel amplifier power supply signal, which is adjustable on a communications slot-to-communications slot basis. During envelope tracking, the parallel amplifier regulates an envelope power supply voltage based on the parallel amplifier power supply signal.
    Type: Application
    Filed: January 24, 2014
    Publication date: July 24, 2014
    Applicant: RF Micro Devices, Inc.
    Inventors: Nadim Khlat, Michael R. Kay, Manbir Singh Nag
  • Publication number: 20140203869
    Abstract: A parallel amplifier and an offset capacitance voltage control loop are disclosed. The parallel amplifier has a parallel amplifier output, which is coupled to an envelope tracking power supply output via an offset capacitive element. The offset capacitive element has an offset capacitive voltage. The offset capacitance voltage control loop regulates the offset capacitive voltage, which is adjustable on a communications slot-to-communications slot basis.
    Type: Application
    Filed: January 24, 2014
    Publication date: July 24, 2014
    Applicant: RF Micro Devices, Inc.
    Inventors: Nadim Khlat, Michael R. Kay, Manbir Singh Nag
  • Patent number: 8750416
    Abstract: An analog radio frequency input and an analog feedback from an output of a radio frequency amplifier are digitized and down-converted. Pre-distortion coefficients are calculated based on the down-converted input and down-converted feedback and the down-converted input is filtered using the pre-distortion coefficients. The filter output is then up-converted to a carrier frequency and converted to analog to be provided to the radio frequency amplifier.
    Type: Grant
    Filed: April 6, 2012
    Date of Patent: June 10, 2014
    Assignee: Broadcast Electronics
    Inventors: Brian Lindemann, Doug Foote, Dan Prysby, John Ribe, David Kroeger
  • Patent number: 8731412
    Abstract: An amplifier implementing with a common base circuit is disclosed. The amplifier includes the common base circuit, a current shunt, and a current supplement. The common base circuit receives an input current. The current shunt shunts the input current based on the average of the output of the pre-amplifier. The current supplement supplements a current shunted by the current shunt.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: May 20, 2014
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Makoto Ito, Taizo Tatsumi
  • Publication number: 20140126622
    Abstract: In one embodiment, a method includes applying, by a transimpedance amplifier at a receiving end of a communication link, equalization to a signal carried by the communication link at the receiving end of the communication link.
    Type: Application
    Filed: November 6, 2012
    Publication date: May 8, 2014
    Applicant: Fujitsu Limited
    Inventors: Scott McLeod, Nikola Nedovic
  • Publication number: 20140085120
    Abstract: An embodiment of the invention includes an analog to digital converter including a sigma delta modulator that generates a feedback signal. The sigma delta modulator includes a quantizer responsive to an input signal and the feedback signal and generates a quantizer output. The sigma delta modulator further includes a chopper-stabilized amplifier that provides a reference signal to the sigma delta modulator, and the chopper-stabilized amplifier is stabilized according to a combination of a chopping signal and the quantizer output.
    Type: Application
    Filed: September 21, 2012
    Publication date: March 27, 2014
    Applicant: Invensense, Inc.
    Inventors: Stanley Bo-Ting Wang, Derek K. Shaeffer
  • Patent number: 8620233
    Abstract: A method of power amplifier predistortion that makes use of a compression detector circuit in a feedback loop in order to adapt the channel gain for changing transmitter behavior. By monitoring the compression behavior of the amplifier, the signal is scaled to compensate for gain and compression point variations in the power amplifier and transmitter, while keeping a predistortion correction function constant.
    Type: Grant
    Filed: April 11, 2008
    Date of Patent: December 31, 2013
    Assignee: Samsung Electroncs Co., Ltd.
    Inventor: Michael Lee Brobston
  • Publication number: 20130293293
    Abstract: Compensation methods and systems for voltage-feedback amplifiers provide improved dynamic performance (i.e., increased bandwidth and the elimination or alleviation of a slew limitation) at high gains by direct feedback of an AC signal (i.e., an intermediate voltage) to an amplifier input without being attenuated by feedback resistor network.
    Type: Application
    Filed: May 4, 2012
    Publication date: November 7, 2013
    Inventor: Quan Wan
  • Publication number: 20130266156
    Abstract: A sensor amplifier arrangement includes an amplifier having a signal input to receive a sensor signal and a signal output to provide an amplified sensor signal, and a feedback path that couples the signal output to the signal input and provides a feedback current that is an attenuated signal of the amplified sensor signal and is inverted with respect to the sensor signal.
    Type: Application
    Filed: April 4, 2012
    Publication date: October 10, 2013
    Applicant: austriamicrosystems AG
    Inventors: Thomas Fröhlich, Matthias Steiner
  • Publication number: 20130222055
    Abstract: A RF power supply system for delivering periodic RF power to a load. A power amplifier outputs a RF signal to the load. A sensor measures the RF signal provided to the load and outputs signals that vary in accordance with the RF signal. A first feedback loop enables control the RF signal based upon power determined in accordance with output from the sensor. A second feedback loop enables control the RF signal based upon energy measured in accordance with signals output from the sensor. Energy amplitude and duration provide control values for varying the RF signal. The control system and techniques are applicable to both pulsed RF power supplies and in various instances to continuous wave power supplies.
    Type: Application
    Filed: February 23, 2012
    Publication date: August 29, 2013
    Applicant: MKS INSTRUMENTS, INC.
    Inventors: David J. Coumou, Richard Pham
  • Publication number: 20130214856
    Abstract: The invention further provides a switching amplifier system. In one embodiment, the switching amplifier system comprises a noise shaper, a corrector, and a pulse width logic. The noise shaper receives a first signal, performs a noise shaping process to process the first signal according to a feedback signal to generate a second signal sliced into a plurality of frames. The corrector adds a plurality of correction pulses respectively to the frames of the second signal to obtain a third signal in such a way that the correction pulse added to the second signal in a target frame selected from the frames has a polarity inverse to that of an original waveform of the second signal in the target frame. The pulse width logic then converts the third signal to a pulse width modulation (PWM) signal.
    Type: Application
    Filed: June 5, 2012
    Publication date: August 22, 2013
    Inventor: Li-Te WU
  • Publication number: 20130162349
    Abstract: The present invention includes a digital controller for use with an ultrasound power amplifier circuit to increase linearity and efficiency of the ultrasound power amplifier circuit. The digital controller includes a digital signal generator and a memory unit that is coupled to the digital signal generator. The memory unit includes a processor that obtains an output signal from the ultrasound power amplifier circuit, calculates error by obtaining a difference between an ideal output signal and the output signal that is obtained from the ultrasound power amplifier circuit, and equalizes an input signal from the digital signal generator to reduce nonlinearity in the output signal of the ultrasound power amplifier circuit. The memory unit includes a look-up-table for storing values of error.
    Type: Application
    Filed: December 21, 2012
    Publication date: June 27, 2013
    Applicant: SOUTHERN METHODIST UNIVERSITY
    Inventor: Southern Methodist University
  • Publication number: 20130162348
    Abstract: Systems and methods for compensating for non-linearity of a non-linear subsystem using predistortion are disclosed. In one embodiment, a system includes a non-linear subsystem and a predistorter configured to effect predistortion of an input signal of the non-linear subsystem such that the predistortion compensates for a non-linear characteristic of the non-linear subsystem. The system also includes an adaptor that adaptively configures the predistorter based on a feedback signal that is representative of an output signal of the non-linear subsystem and an input signal that is representative of the input signal of the non-linear subsystem. The adaptor generally models the non-linear subsystem as a concatenation of a non-linear model that corresponds to the non-linear characteristic of the non-linear subsystem and a linear model that corresponds to a known linear characteristic of the non-linear subsystem.
    Type: Application
    Filed: December 21, 2011
    Publication date: June 27, 2013
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Chunlong Bai, Chunyun Jian
  • Publication number: 20130147548
    Abstract: A linear amplifier that comprises a signal input terminal that receives an input signal having a first common mode voltage, a voltage amplifier having a non-inverting input terminal that receives a second common mode voltage, a first and a second input resistance connected in series from the signal input terminal to the inverting input terminal of the voltage amplifier, a feedback resistance connected between the inverting input terminal and the output terminal of the voltage amplifier, and a constant current source. The constant current source supplies a constant current to a middle node between the first and the second input resistances. The constant current generates a voltage drop, which is equal to a difference between the first and the second common mode voltages, across the first input resistance. Accordingly, the common mode voltage of the output signal is directly determined by the second common mode voltage.
    Type: Application
    Filed: December 7, 2012
    Publication date: June 13, 2013
    Applicant: KAWASAKI MICROELECTRONICS, INC.
    Inventor: KAWASAKI MICROELECTRONICS, INC.
  • Publication number: 20130120059
    Abstract: An amplifier circuit includes: an input pad to receive a current signal; a conversion section to convert the current signal into a voltage signal; an inductor electrically connected in series between the input pad and the conversion section; and a storage element, one end of the storage element electrically coupled between the inductor and the conversion section, the other end of the storage element electrically coupled to a ground.
    Type: Application
    Filed: September 5, 2012
    Publication date: May 16, 2013
    Applicant: FUJITSU LIMITED
    Inventor: Hideki OKU
  • Publication number: 20130088291
    Abstract: Embodiments of circuitry, which includes an operational transconductance amplifier and a passive circuit, are disclosed. The passive circuit is coupled to the operational transconductance amplifier. Further, the passive circuit receives an input signal and the operational transconductance amplifier provides an output current, such that the passive circuit and the OTA high-pass filter and integrate the input signal to provide the output signal.
    Type: Application
    Filed: October 9, 2012
    Publication date: April 11, 2013
    Applicant: RF MICRO DEVICES, INC.
    Inventor: Philippe Gorisse
  • Publication number: 20130075608
    Abstract: According to example embodiments, an image sensor includes a charge sensing amplifier configured to amplify charges sensed by a sensing unit. The charge sensing amplifier includes an input terminal, an amplification terminal, an output terminal, a first capacitor connected between the input terminal and the amplification terminal, a first switch connected between the input terminal and the amplification terminal, a second capacitor connected between the amplification terminal and the output terminal, and a second switch connected between the output terminal and a reference voltage terminal.
    Type: Application
    Filed: August 29, 2012
    Publication date: March 28, 2013
    Applicants: KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY, SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Sang-wook HAN, Hyun-sik KIM, Gyu-Hyeong CHO, Chang-jung KIM, Jae-chul PARK, Young-hun SUNG, Young KIM, Jun-hyeok YANG
  • Publication number: 20130069719
    Abstract: An amplifier circuit comprises a measurement path with an amplifier (1) for providing an output voltage (Vout) depending on a measuring current (Ipd) with a first and a second amplifier input (11, 12), and an amplifier output (13). A return path of the amplifier circuit comprises a first filter (2), an auxiliary amplifier (3) and a second filter (4). In this case, the first filter (2) is designed to filter a DC voltage from the output voltage (Vout) and is connected to the amplifier output (13). The auxiliary amplifier (3) serves to convert an input voltage (Vfil) into an output current (Ifil) and has a first and a second auxiliary amplifier input (31, 32) and an auxiliary amplifier output (33). In this case, the first auxiliary amplifier input (31) is connected to the first filter (2). The second filter (4) is designed to filter noise from the output current (Ifil) and couples the auxiliary amplifier output (33) to the first amplifier input (11).
    Type: Application
    Filed: March 3, 2011
    Publication date: March 21, 2013
    Applicant: Schloss Premstatten
    Inventors: Mark Niederberger, Vincenzo Leonardo
  • Publication number: 20130057340
    Abstract: Provided are a highly efficient, low waveform distortion power supply device and a power amplifying apparatus with high efficiency and high linearity using the device as a power supply. A power supply device of the present invention comprises a linear amplifier unit 400 which linearly amplifies an input signal and outputs it as an electric current Ic, and a switching amplification control unit 500, which outputs an electric current Im using a plurality of switching amplifying units 601, 602, . . . 60n for outputting respective predetermined voltages on the basis of the magnitude of the electric current Ic outputted from said linear amplifier unit 400; and it generates an output voltage Vout according to the waveform of the input signal, and outputs an electric current Tout which is a combination of the electric currents Ic and Im.
    Type: Application
    Filed: May 13, 2011
    Publication date: March 7, 2013
    Applicant: NEC CORPORATION
    Inventors: Kazuaki Kunihiro, Yasushi Watanabe
  • Publication number: 20120319770
    Abstract: An output buffer circuit capable of enhancing stability includes an operational amplifier, a capacitive load and an output control unit. The operational amplifier has a positive input terminal, a negative input terminal and an output terminal, and generates an output voltage to the output terminal according to an input voltage received by the positive input terminal. The output control unit is coupled between the output terminal of the operational amplifier and the capacitive load, and is utilized for controlling electrical connection between the output terminal of the operational amplifier and the capacitive load to form a signal output path and for adjusting impedance of the signal output path when the signal output path is formed. The output control unit comprises a plurality of output switches for individually turning on or off the electrical connection between the output terminal and the capacitive load of the operational amplifier.
    Type: Application
    Filed: August 23, 2012
    Publication date: December 20, 2012
    Inventors: Xie-Ren Hsu, Ji-Ting Chen, Yao-Hung Kuo
  • Publication number: 20120314880
    Abstract: A driver circuit includes a first driver amplifier that is configured to generate a first output in response to a first reference voltage input and a first audio input; a second driver amplifier that is configured to generate a second output in response to the first reference voltage and a second audio input; and a common mode (CM) amplifier, coupled to the first driver amplifier and the second driver amplifier. The CM amplifier is configured to generate an output in response to a second reference voltage input, the first reference voltage input being a divided version of the output. Gains of the first driver amplifier, second driver amplifier and the CM amplifier are equal. Noise at the output appears across a plurality of resistors coupled at the outputs of the first driver amplifier, second driver amplifier and the CM amplifier and cancels with respect to the output of the CM amplifier.
    Type: Application
    Filed: June 10, 2011
    Publication date: December 13, 2012
    Applicant: Texas Instruments Incorporated
    Inventor: Vineet Mishra
  • Publication number: 20120293250
    Abstract: The invention relates to a configurable low noise amplifier circuit which is configurable between a first topology in which the low noise amplifier circuit includes a degeneration inductance whereby the low noise amplifier circuit operates as an inductively degenerated low noise amplifier, and a second topology in which the low noise amplifier circuit includes a feedback resistance whereby the low noise amplifier circuit operates as a resistive feedback low noise amplifier.
    Type: Application
    Filed: December 1, 2011
    Publication date: November 22, 2012
    Inventors: Jari Heikkinen, Jonne Riekki, Jouni Kaukovuori
  • Publication number: 20120249233
    Abstract: The present invention concerns the field of power amplifiers and in particular the enhancement of the performance of the amplifier by a feedback loop acting on the input signal.
    Type: Application
    Filed: November 16, 2010
    Publication date: October 4, 2012
    Inventors: Amirhooshang Farahani Samani, Jeyran Hezaveh, Ali Talebi
  • Publication number: 20120218036
    Abstract: Techniques are disclosed for canceling an offset component (e.g., dc component or dc offset) in an amplifier circuit. For example, an apparatus comprises an amplifier circuit with an amplifier element and a feedback resistor network coupled between an output of the amplifier element and an input of the amplifier element. The apparatus also comprises a current source coupled to the feedback resistor network, the current source generating a current signal that generates a voltage in a first portion of the feedback resistor network that cancels an offset component present in an input signal received by the amplifier circuit. A second portion of the feedback resistor network may be adjustable so that a gain applied to the input signal is adjustable while the offset component is canceled from the input signal. One or more resistors in the feedback resistor network may be composed of the same or substantially similar material as one or more resistors associated with the current source.
    Type: Application
    Filed: February 24, 2011
    Publication date: August 30, 2012
    Inventor: Robert Alan Norman
  • Publication number: 20120075015
    Abstract: An amplifier circuit and method are described for linearizing the gain of a voltage or current feedback amplifier that is non-linear.
    Type: Application
    Filed: September 27, 2010
    Publication date: March 29, 2012
    Applicant: EADS North America, Inc.
    Inventor: John R. Coupland
  • Publication number: 20120044019
    Abstract: Power amplifier for amplifying an electric input signal in an operational frequency range and providing an output signal, comprising switching means (12) for generating a block wave signal by alternately switching the block wave signal to a first supply voltage or a second supply voltage, input means for receiving the electric signal and driving the switching means, wherein the input means comprises an integrator circuit (10) integrating an error signal formed by a difference between the output signal and the electric input signal and providing an integrator gain in the operational frequency range, the power amplifier further comprising a local feedback circuit (18), and a global feedback circuit (20), an output of the integrator circuit being connected the input of the switching mean A limiter circuit (22) is connected to receive the electric input signal and an output signal of the integrator circuit and connected to the integrator circuit for limiting the gain of the integrator circuit when detecting a dif
    Type: Application
    Filed: April 28, 2010
    Publication date: February 23, 2012
    Applicant: Abletec AS
    Inventor: Patrik Broström
  • Patent number: 8095088
    Abstract: A radio frequency transmitter comprising a modem which receives one or more input data signals and an adaptive predistortion signal and provides a baseband in-phase signal and a baseband quadrature signal. The transmitter may comprise a power amplifier module which receives the in-phase and quadrature phase signals and provides a radio frequency output signal. A predistortion module receives the radio frequency signal, downconverts the radio frequency signal to an intermediate frequency signal, and downconverts the intermediate frequency signal to a baseband feedback signal. The transmitter samples the feedback signal and provides an adaptive predistortion signal to the modem.
    Type: Grant
    Filed: May 17, 2007
    Date of Patent: January 10, 2012
    Assignee: Harris Stratex Networks Operating Corporation
    Inventors: Ying Shen, James Laudolff, Travis Mashburn, Todd Nichols, David C. Schafer, Thanh H. Nguyen
  • Publication number: 20120001687
    Abstract: A receiving apparatus converges a gain to a target gain even when a fish bone effect signal is included having a low power period in which signal power decreases abruptly compared to average signal power. The receiving apparatus (100) receives a signal including the fish bone effect signal having the low power period (FBE signal period) in which signal power decreases abruptly compared to average signal power. A FBE detecting section (133) detects an FBE signal period of a low power period based on a gain error corresponding to a difference between target power and average signal power of the received signal of the adjusted gain. Further, the gain error correcting section (134) selects a lower value than 1 as a convergence coefficient in the FBE signal period of a low power period, multiplies the gain error with the selected convergence coefficient and corrects the gain error.
    Type: Application
    Filed: June 30, 2011
    Publication date: January 5, 2012
    Applicant: PANASONIC CORPORATION
    Inventors: Tomoya URUSHIHARA, Isao Imazeki
  • Publication number: 20110298536
    Abstract: To accelerate the convergence of distortion compensation and improve the performance of distortion compensation in a distortion compensation amplifier which performs distortion compensation with a pre-distortion scheme. Level detecting means 1, distortion compensation aspect storing means 3, distortion providing means 4 perform distortion compensation, and amplifying means 8 amplifies a signal. Feedback signal taking means 9, 11 to 16 take a feedback signal, and distortion level detecting means 9, 11, 12, 17, and 18 detect the level of distortion contained in the feedback signal. Control means 19 updates the storage content of the distortion compensation aspect storing means so as to reduce the error component between the signal to be amplified and the feedback signal at the time of start of distortion compensation processing, and updates the content of the distortion compensation aspect storing means so as to reduce the detected level of distortion when the error component is reduced.
    Type: Application
    Filed: November 20, 2009
    Publication date: December 8, 2011
    Inventors: Takashi Okazaki, Yoshiaki Doi
  • Publication number: 20110241771
    Abstract: Conventional muting circuitry for amplifiers (which usually uses clamps) generally has about 20-30 dB of attenuation. Here, an integrated circuit or IC is provided that includes an amplifier, switch networks, and a controller. The controller provides control signals to the switch network to provide mute functionality by actively muting the amplifier. In particular, feedback is provided through at least one of the switch networks to drive the output of the amplifier to null or ground so as to provide 70-80 dB (or more) of attenuation.
    Type: Application
    Filed: March 30, 2010
    Publication date: October 6, 2011
    Applicant: Texas Instruments Incorporated
    Inventors: Allan N. Nielsen, Kim N. Madsen
  • Patent number: 8023588
    Abstract: Apparatus and methods control predistortion of an RF transmitter. A base station or a mobile station can utilize predistortion to improve linearity characteristics of the RF power amplifier. When used effectively, predistortion limits spectral growth such that the amplified signal complies with regulatory requirements. With respect to bursty signals, specific improvement techniques are disclosed. A first technique is related to adaptation using only a smaller subset of samples of a burst. A second technique is related to selective application of digital predistortion, such as, only under high power conditions for a power amplifier. A third technique is directed to adaptation of less than all of the coefficients. These improvements permit the use of a smaller and less expensive amplifier for a given power class and can lengthen battery life for a mobile unit.
    Type: Grant
    Filed: April 8, 2008
    Date of Patent: September 20, 2011
    Assignee: PMC-Sierra, Inc.
    Inventors: Jeremy Benson, William D. Warner, Paul V. Yee
  • Publication number: 20110204972
    Abstract: To efficiently obtain two outputs including one at a normal level and the other at an excessive level. An input signal input to the negative input terminal of an operational amplifier (14) having a negative feedback path is amplified to output an output signal. Signal combining units (18, 20, 22) are provided for adding in a weighted manner a negative input terminal side signal obtained by combining the input signal input to the negative input terminal of the operational amplifier (14) and a feedback signal from the negative feedback path and the output signal from the operational amplifier to output a combined signal, so that two signals, namely the output signal from the operational amplifier (14) and the combined signal, are obtained.
    Type: Application
    Filed: February 22, 2011
    Publication date: August 25, 2011
    Applicant: ON SEMICONDUCTOR TRADING, LTD.
    Inventor: Masahito Kanaya
  • Publication number: 20110169573
    Abstract: A step gain amplifier has an amplifier with an input and an output, and a bias circuit connected to the input and to a bias node. A passive feedback circuit using only passive elements connects the output to the input. A control circuit is connected to the bias circuit at the bias node.
    Type: Application
    Filed: January 11, 2010
    Publication date: July 14, 2011
    Inventors: Bun Kobayashi, Steven W. Schell, Yonghan Chris Kim, Pei-Ming Daniel Chow, Mau-Chung Frank Chang
  • Publication number: 20110163802
    Abstract: An amplification arrangement comprises a signal-processing element (SVE) with an integrator element (INT) that is coupled on the input side with a first input (E1) for feeding the input signal and with a second input (E2) for feeding a feedback signal. The signal-processing element (SVE) is designed to set a respective level of the input signal and/or the feedback signal as a function of a control signal. The amplifier arrangement furthermore comprises a pulse modulator (PM) that is designed to generate a pulse signal on a pulse output (POT) as a function of a signal applied on the output (SOT) of the signal-processing element (SVE). An output stage (OST) comprises a switching element (SW) that is designed to connect supply-voltage terminals (V1, V2, GND) to an output terminal (OOT) that is coupled with an amplifier output (AOT) and the second input (E2), and a control unit (CU) for driving the switching element (SW) that is coupled with the pulse output (POT).
    Type: Application
    Filed: May 27, 2009
    Publication date: July 7, 2011
    Inventor: Bernhard Greimel-Rechling
  • Publication number: 20110133832
    Abstract: The invention relates to a digital amplifier for providing a desired electrical output power, the amplifier comprising a power source (100) for generating the electrical output power, the amplifier further comprising: a digital input adapted for receiving a digital input signal (112), the digital input signal (112) representing the desired electrical output power level, a reference power generator (124) for generating an analogue reference power controlled by the digital input signal (112), a power measurement component (142; 128) adapted for measuring the power differential between the electrical output power provided by the power source (100) and the analogue reference power, an analogue-to-digital converter (130) adapted for converting the power differential into a digital power differential value (132), a combiner adapted for providing a combined digital signal (136) by adding the digital power differential value (132) to the digital value input to the reference power generator (124) for generating the an
    Type: Application
    Filed: July 3, 2009
    Publication date: June 9, 2011
    Applicant: Koninklijke Philips Electronics N.V.
    Inventor: Martin Hollander
  • Patent number: 7932778
    Abstract: An amplifier generates a tri-level output signal in response to an input signal that is pulse-width modulated. The amplifier is filterless and DC free. A control block supplies a multitude of pulse-width modulated (PWM) signals in response to the received digital input signal. A pair of the PWM signals are applied to the signal generator which in response supplies a third signal to the integrator. The integrator integrates the third signal in accordance with a feedback signal.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: April 26, 2011
    Assignee: Marvell International Ltd.
    Inventor: Sasan Cyrusian
  • Publication number: 20110074502
    Abstract: The invention relates to an amplifier capable of delivering a plurality of output signals, these output signals being controlled by a plurality of input signals. A multiple-input and multiple-output amplifier of the invention comprises a common input terminal, 4 signal input terminals, 4 signal output terminals, a common terminal amplifier, 4 active sub-circuits and a feedback network. Each active sub-circuit has a sub-circuit input terminal connected to one of the signal input terminals, a sub-circuit output terminal connected to one of the signal output terminals and a sub-circuit common terminal. The feedback network has four C terminals and one R terminal. Each of said C terminals of the feedback network is coupled to the sub-circuit common terminal of one of said active sub-circuits. The output terminal of the common terminal amplifier is coupled to said R terminal of the feedback network.
    Type: Application
    Filed: November 29, 2010
    Publication date: March 31, 2011
    Applicant: EXCEM
    Inventors: Frédéric BROYDE, Evelyne CLAVELIER
  • Patent number: 7915995
    Abstract: A resistive circuit includes a first terminal and a second terminal and polycrystalline first and second resistive segments coupled between the first and second terminals. A third terminal A is coupled to the first resistive segment, and a third terminal B is coupled to the second resistive segment. The third terminal A has a first voltage with respect to the first terminal, and the third terminal B has a second voltage with respect to the second terminal. With this arrangement, the non-linearity of resistance of the first resistive segment at least partially compensates for non-linearity of resistance of the second resistive segment.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: March 29, 2011
    Assignee: Cirrus Logic, Inc.
    Inventors: Hua Yang, Ammisetti Prasad, John L. Melanson
  • Publication number: 20110068863
    Abstract: A reconfigurable network arrangement of resistors and switches is constructed so that it can be coupled to one or more operational amplifiers and selectively programmed so as to set the gain of the resulting amplifier. The configuration of the network arrangement of resistors and switches to include resistors that can be connected in the feedback path in series and in parallel with each other is such as to provide a wider selection of gain settings, without the need to increase the physical area of the switches on a integrated circuit arrangement.
    Type: Application
    Filed: August 16, 2010
    Publication date: March 24, 2011
    Applicant: THAT CORPORATION
    Inventor: Gary Hebert
  • Patent number: 7907904
    Abstract: A wireless device dynamically controls a power level for each channel in a transmission spectrum. The power level is adjusted based on characteristics of signals received in the adjacent channels which results in the wireless device working at maximum ranges consistent with not causing interference to other users of the spectrum.
    Type: Grant
    Filed: January 24, 2005
    Date of Patent: March 15, 2011
    Assignee: Intel Corporation
    Inventors: Alan E. Waltho, Jeffrey Schiffer