Variable Impedance For Signal Channel Controlled By Separate Control Path Patents (Class 330/144)
  • Patent number: 10249930
    Abstract: An electromagnetic coupler includes a first transmission line connecting an input port to an output port. A second transmission line adjacent the first transmission line connects a coupled port and an isolation port. The electromagnetic coupler provides a coupled signal at the coupled port, which is representative of an input signal at the input port. The amplitude of the coupled signal is related to the amplitude of the input signal by a coupling factor. A tuning element is provided adjacent to the first or second transmission line and is coupled to an impedance. Varying impedance values cause an adjustment to the coupling factor and reactive impedance values provide frequency filtering effects.
    Type: Grant
    Filed: April 27, 2017
    Date of Patent: April 2, 2019
    Assignee: SKYWORKS SOLUTIONS, INC.
    Inventors: Nuttapong Srirattana, Sriram Srinivasan, Zhiyang Liu
  • Patent number: 10243530
    Abstract: An attenuation circuit with stages having constant dB steps between stages is provided. The attenuation circuit can be configured as a ladder network using resistors having three different values. A first resistor can be connected between the last stage of the attenuation circuit and ground and have a first predetermined resistance. One or more second resistors can be connected in each stage and have a second predetermined resistance based on the first predetermined resistance and the dB step between stages. One or more third resistors can be connected in parallel to the first resistor for the remaining stages and have a third predetermined resistance based on the first predetermined resistance and the dB step between stages.
    Type: Grant
    Filed: April 29, 2017
    Date of Patent: March 26, 2019
    Assignee: ADTRAN, Inc.
    Inventor: Daniel M. Joffe
  • Patent number: 9852322
    Abstract: A finger biometric sensing device may include drive circuitry for generating a drive signal and an array of finger biometric sensing pixel electrodes cooperating with the drive circuitry and generating a detected signal based upon placement of a finger adjacent the array. The detected signal may include a drive signal component and a sense signal component superimposed thereon. A gain stage may be coupled to the array and drive signal nulling circuitry may be coupled to the gain stage for reducing the drive signal component from the detected signal. The drive signal nulling circuitry may include a first digital-to-analog converter (DAC) generating an inverted scaled replica of the drive signal for the gain stage. Error compensation circuitry includes a memory storing error compensation data and a second DAC coupled in series with the first DAC compensating an error in the inverted scaled replica based upon the error compensation data.
    Type: Grant
    Filed: March 19, 2015
    Date of Patent: December 26, 2017
    Assignee: APPLE INC.
    Inventors: Pavel Mrazek, Giovanni Gozzini, Jean-Marie Bussat
  • Patent number: 9825366
    Abstract: A printed circuit board antenna and a printed circuit board are disclosed. The printed circuit board antenna includes a feeding part having at least one first branch; a coupling interdigital part having at least one second branch, where a gap is formed between the first branch and the second branch; a grounding part, where a gap is formed between the grounding part and the feeding part, a gap is formed between the grounding part and the coupling interdigital part, an opening is provided on the grounding part, and a feeding point of the feeding part extends out from the opening. The embodiments of the present invention resolve a problem of relatively low efficiency when high-frequency bandwidth of an antenna is relatively wide, implementing that efficiency meets a product requirement in an entire range of bandwidth.
    Type: Grant
    Filed: December 17, 2014
    Date of Patent: November 21, 2017
    Assignee: HUAWEI TECHNOLOGIES CO., LTD.
    Inventors: Zhenghao Li, Yao Lan, Lintao Jiang, Jie Qi, Yi Zhang, Yundi Yao
  • Patent number: 9735795
    Abstract: An analog-to-digital converter arrangement may include an analog amplifier with variable gain; an analog-to-digital converter; a digital reconstruction element including elements to reduce an influence of transients during a change of the variable gain of the analog amplifier.
    Type: Grant
    Filed: November 12, 2013
    Date of Patent: August 15, 2017
    Assignee: Infineon Technologies AG
    Inventors: Dietmar Straeussnigg, Andreas Wiesbauer
  • Patent number: 9705179
    Abstract: An antenna structure includes a feed portion, a ground portion, a connecting portion, a first metallic sheet, a second metallic sheet, and a coupling portion. The connecting portion is electrically connected to the feed portion. The first metallic sheet is electrically connected to the ground portion. The second metallic sheet is spaced apart from the first metallic sheet and is electrically connected to the connecting portion. The coupling portion is coupled to the connecting portion and spaced apart from the first metallic sheet.
    Type: Grant
    Filed: December 11, 2014
    Date of Patent: July 11, 2017
    Assignee: Chiun Mai Communication Systems, Inc.
    Inventor: Yen-Hui Lin
  • Patent number: 9692378
    Abstract: Disclosed examples include programmable gain amplifier (PGA) circuits with an operation amplifier circuit having a first amplifier input and a second amplifier input including a plurality of second input nodes, a resistor array including a plurality of resistor sections connected in series with one another between the amplifier output and a reference voltage node, and a trim select circuit coupled between the second amplifier input and the resistor array circuit to deliver a feedback voltage signal to each individual one of the second input nodes from a given selected one of a plurality of the tap points of the resistor array circuit according to a trim code to provide analog gain trimming by interpolation.
    Type: Grant
    Filed: September 7, 2016
    Date of Patent: June 27, 2017
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Aniruddha Roy, Nitin Agarwal
  • Patent number: 9503038
    Abstract: A current controlling device includes: a first resistive circuit arranged to selectively conduct a first current to a first output terminal from a first input terminal; and a second resistive circuit arranged to selectively conduct a second current to a second output terminal from the first input terminal; wherein when the first resistive circuit conducts the first current to the first output terminal and when the second resistive circuit does not conduct the second current to the second output terminal, the first input terminal has a first input impedance; when the first resistive circuit does not conduct the first current to the first output terminal and when the second resistive circuit conducts the second current to the second output terminal, the first input terminal has a second input impedance substantially equal to the first input impedance.
    Type: Grant
    Filed: November 13, 2014
    Date of Patent: November 22, 2016
    Assignee: MEDIATEK INC.
    Inventors: Min-Hua Wu, Chih-Hong Lou, Yen-Chuan Huang, Chi-Yun Wang
  • Patent number: 9503132
    Abstract: A wireless communication apparatus includes an amplifying unit that amplifies an input signal that includes signals with different frequencies of a first frequency and the second frequency; a measuring unit that measures a level of inter modulation distortion generated in a signal obtained by the input signal being amplified by the amplifying unit; a determining unit that determines whether the level of the inter modulation distortion measured by the measuring unit is equal to or greater than a regulation value that is previously stored; and a control unit that decreases, when a result of the determination obtained by the determining unit indicates that the level of the inter modulation distortion is equal to or greater than the regulation value, a level of a signal input to the amplifying unit.
    Type: Grant
    Filed: July 29, 2015
    Date of Patent: November 22, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Mutsuhito Ota, Setsuya Nagaya, Shinichi Kawai, Yusuke Yamamori
  • Patent number: 9314648
    Abstract: A system, method and apparatus tracks targets (e.g., tumors) during treatment (e.g., radiation therapy) using a radar motion sensor by generating a microwave signal, radiating the microwave signal to a subject, and receiving a modulated microwave signal from the subject. The modulated microwave signal is processed to provide a subject motion information using a sensor having an arctangent-demodulation microwave interferometry mode. A location of a target on or within the subject is determined based on the subject motion information and a three-dimensional model for the subject and the target. One or more control signals are generated based on the location of the target, and the treatment device is controlled using the one or more control signals to treat the target on or within the subject.
    Type: Grant
    Filed: December 23, 2012
    Date of Patent: April 19, 2016
    Assignee: Texas Tech University System
    Inventors: Changzhi Li, Changzhan Gu
  • Patent number: 9319016
    Abstract: It is possible to enable automatic on/off switching of a pad and to prevent frequent occurrence of on/off switching of a pad even when a user carries out fine manipulation. A level adjustment device includes a pad which attenuates a signal by a predetermined level, an amplifier which is provided at the back of the pad to adjust the level of the signal with a variable amplification rate or attenuation rate, and a level adjustment unit which, when the pad is off, uses only the amplifier and, when the pad is on, uses the amplifier and the pad to adjust the level of the acoustic signal. The setting of a level adjustment value by the level adjustment unit is received, when the level adjustment value reaches a predetermined switching point Tsw, the on/off of the pad is switched, and when an instruction is issued to start a performance mode, the value of the switching point Tsw is changed so as to be away from the level adjustment value at the point of time of the instruction.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: April 19, 2016
    Assignee: Yamaha Corporation
    Inventor: Masaru Aiso
  • Patent number: 9271239
    Abstract: A device includes a multi-mode low noise amplifier (LNA) having a first amplifier stage, and a second amplifier stage coupled to the first amplifier stage, the second amplifier stage having a plurality of amplification paths configured to amplify a plurality of carrier frequencies, the first amplifier stage configured to bypass the second amplifier stage when the first amplifier stage is configured to amplify a single carrier frequency.
    Type: Grant
    Filed: February 14, 2014
    Date of Patent: February 23, 2016
    Assignee: Qualcomm Incorporated
    Inventors: Muhammad Hassan, Yiwu Tang, Klaas van Zalinge, Chuan Wang, Dongling Pan
  • Patent number: 9184713
    Abstract: A variable gain amplifier circuit (200) comprising an amplifier element (202) having an input (208, 210) and an output (220, 222); a feedback loop (224, 226) having a feedback impedance (228, 230) connected between the input (208, 210) and output (232, 234) of the amplifier element (202); an input branch (212, 214) having an input resistance connected between an input of the variable gain amplifier circuit and the input (208, 210) of the amplifier element (202); and a plurality of switches for selecting a gain of the variable gain amplifier circuit (200); characterised in that the variable gain amplifier circuit (200) further comprises an intermediate element (204) having an input and an output, the input being connected to a node between one of the switches and the feedback impedance (228, 230), such that the output can provide a signal which can be used to attenuate a signal component in the output (220, 222) of the amplifier element (202) caused by a non-linearity in the plurality of switches.
    Type: Grant
    Filed: November 26, 2009
    Date of Patent: November 10, 2015
    Assignee: QUALCOMM TECHNOLOGIES INTERNATIONAL, LTD.
    Inventor: Hashem Zare-Hoseini
  • Patent number: 8975964
    Abstract: A high performance digitalized Programmable Gain Amplifier (PGA). In prior art circuit, a dual-ladder DAC is employed for gain control, the back gate leakage of NMOS resistors in the fine ladder conquers fine ladder nominal current and it produces non-monotonic gain scallop. Two new art design techniques: (1) adaptively control the fine ladder; and (2) use dummy PMOS brunch device leakage compensates for the NMOS resistor device leakage, are proposed so that the non-monotonic scallops are substantially eliminated and 13-bit resolution/accuracy PGA has been achieved.
    Type: Grant
    Filed: February 5, 2013
    Date of Patent: March 10, 2015
    Assignee: Texas Instruments Incorporated
    Inventors: Qunying Li, Wenxiao Tan, Gregory Swize
  • Patent number: 8912850
    Abstract: An amplification circuit, which may be in a receive path of a communication device, includes an amplifier including at least a first amplification device and a switchable attenuation circuit. The switchable attenuation circuit includes one or more switches and a plurality of attenuation devices and is operable to provide different levels of attenuation to an input signal prior to input to the amplifier depending on the status of the one or more switches. The attenuation devices may be capacitors, wherein the capacitors may be arranged to form a capacitive divider with a level of attenuation dependent on the status of the switches. The switchable attenuation circuit may be a switched capacitive attenuation ladder of n stages, n being any integer, each ladder stage including a capacitive divider. The amplification circuit may also include a switch, which when closed provides an unattenuated path for the input signal to the amplifier input.
    Type: Grant
    Filed: September 25, 2013
    Date of Patent: December 16, 2014
    Assignee: Broadcom Corporation
    Inventors: Xavier (Javier) Trulls Fortuny, Diego Mateo Pena, Adria Bofill-Petit
  • Patent number: 8884693
    Abstract: A variable gain amplifier circuit is provided. The circuit includes an operational amplifier for amplifying and outputting an input signal according to a cutoff frequency and a gain, a feedback resistor for changing a first resistance according to a first digital control code value which determines the cutoff frequency, and an input resistor for changing a second resistance according to a second digital control code value which is determined based on a difference of the first digital control code value and a gain code value. The gain is determined by a ratio of the first resistance and the second resistance and linearly changes on a decibel (dB) basis according to the first digital control code value, the cutoff frequency is inversely proportional to the first resistance and linearly changes on a log scale, and the variable gain can be easily set using the control code.
    Type: Grant
    Filed: December 13, 2012
    Date of Patent: November 11, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jong-Woo Lee
  • Patent number: 8854125
    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: Grant
    Filed: December 7, 2012
    Date of Patent: October 7, 2014
    Assignee: MegaChips Corporation
    Inventor: Takashi Ikeda
  • Patent number: 8836425
    Abstract: A variable gain amplifier has an attenuator having an input and a series of tap points, and a series of low-inertia switches, each switch coupled to a corresponding one of the tap points to steer outputs from the attenuator to an output terminal. An amplifier has an input cell, a load coupled to an output of the input cell, a buffer having an input coupled to the load, a feedback network coupled between an output of the buffer and the input cell, and a variable filter cell coupled to the input cell.
    Type: Grant
    Filed: May 2, 2013
    Date of Patent: September 16, 2014
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Patent number: 8810275
    Abstract: A direct current-to-direct current (‘DC/DC’) converter for delivering a load to an electrical component, the DC/DC converter including: a coupled inductor, wherein the coupled inductor receives a source input voltage level and a outputs an output voltage level; a transient winding; and a variable impedance switch coupled to the transient winding, the variable impedance switch configured to operate by adjusting a delivered resistance level in dependence upon a change in the load to be delivered to the electrical component by the DC/DC converter.
    Type: Grant
    Filed: December 7, 2012
    Date of Patent: August 19, 2014
    Assignee: International Business Machines Corporation
    Inventors: Jamaica L. Barnette, Bobby J. Hemingway
  • Patent number: 8803600
    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: Grant
    Filed: August 23, 2012
    Date of Patent: August 12, 2014
    Assignee: NOVATEK Microelectronics Corp.
    Inventors: Xie-Ren Hsu, Ji-Ting Chen, Yao-Hung Kuo
  • Patent number: 8750810
    Abstract: Exemplary embodiments are directed to a transmitter with a power amplifier and a switched output matching circuit implementing a plurality of output paths for a plurality of operating modes is described. The power amplifier receives an input RF signal and provides an amplified RF signal. An output matching network performs impedance transformation from low impedance at the power amplifier output to higher impedance at the matching network output. The plurality of output paths are coupled to the output matching network. Each output path provides a different target output impedance for the power amplifier and routes the amplified RF signal from the power amplifier to an antenna when that output path is selected. Each output path may include a matching network coupled in series with a switch. The matching network provides the target output impedance for the power amplifier when the output path is selected. The switch couples or decouples the output path to/from the power amplifier.
    Type: Grant
    Filed: November 20, 2009
    Date of Patent: June 10, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Nathan Pletcher, Aristotele Hadjichristos, Yu Zhao, Babak Nejati
  • Publication number: 20140152385
    Abstract: A bidirectional matching network is disclosed. In an exemplary embodiment, an apparatus includes a first matching circuit connected in a first signal path between a node and a first amplifier, the first matching circuit configured to translate an off-state impedance of the first amplifier to a first translated off-state impedance. The apparatus also includes a second matching circuit connected in a second signal path between the node and a second amplifier. The second matching circuit configured to translate an off-state impedance of the second amplifier to a second translated off-state impedance. The second translated off-state impedance is configured to reduce power loss associated with a first signal flowing in the first signal path and the first translated off-state impedance is configured to reduce power loss associated with a second signal flowing in the second signal path.
    Type: Application
    Filed: November 30, 2012
    Publication date: June 5, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Danial Ehyaie, Mazhareddin Taghivand
  • Publication number: 20140070884
    Abstract: A circuit for amplifying the power of signal, the circuit comprising a power amplifier, a transformer and a load; wherein the transformer comprises a primary inductor and a secondary inductor, the first inductor being coupled to, and capable of being driven by, the power amplifier, and the secondary inductor coupled to, and capable of driving, the load; wherein a first one of the primary and secondary inductors is a variable inductor whose inductance is variable responsive to a control input in order to change the output power of the amplifier.
    Type: Application
    Filed: September 10, 2012
    Publication date: March 13, 2014
    Applicant: Cambridge Silicon Radio Limited
    Inventors: Giuseppe Gramegna, Konstantinos Manetakis
  • Publication number: 20130314154
    Abstract: The present disclosure provides a signal processing apparatus including: a short-circuiting controlling section configured to control whether or not the input side of a resistor connected between an input terminal and an output terminal and the output terminal are to be short-circuited in response to a signal level of a signal inputted from the input terminal; and a connection controlling section configured to control whether or not a resistor member is to be connected between the output terminal and a reference potential in response to the signal level of the signal, wherein at least one of the short-circuiting controlling section and the connection controlling section includes a plurality of switches disposed in parallel to each other for changing over a state thereof between open and closed states at signal levels different from each other.
    Type: Application
    Filed: May 21, 2013
    Publication date: November 28, 2013
    Applicant: SONY CORPORATION
    Inventor: Naoto Yoshikawa
  • Publication number: 20130285741
    Abstract: Embodiments of apparatuses, methods, and systems for a radio frequency amplification circuit providing for fast loadline modulation are generally described herein. Other embodiments may be described and claimed.
    Type: Application
    Filed: April 30, 2012
    Publication date: October 31, 2013
    Applicant: TRIQUINT SEMICONDUCTOR, INC.
    Inventor: Peter V. Wright
  • Patent number: 8570139
    Abstract: Provided is an analog amplifier for amplifying an analog signal and an analog filter, and in particular, an apparatus and method for controlling gain and cutoff frequency of the variable gain amplifier and the variable cutoff frequency filter that is capable of changing the gain and cutoff frequency. The variable resister includes a plurality of resister segments in the variable resister and, when a plurality of resistance candidates for the variable resister are arranged in order of size, the resistance candidates form a geometric series.
    Type: Grant
    Filed: July 25, 2011
    Date of Patent: October 29, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jongwoo Lee
  • Publication number: 20130278333
    Abstract: Techniques for optimizing a cascade gain device comprising at least two gain stages are disclosed. A first noise figure associated with the first gain stage is incrementally increased by a plurality of noise figure increments determined based, at least in part, on a minimum noise figure and a maximum noise figure associated with the first gain stage. At each of the plurality of noise figure increments, at least a gain value that corresponds to the noise figure increment is calculated. One of the plurality of noise figure increments and the corresponding gain value is selected as an optimum noise figure of the first gain stage and an optimum gain value of the first gain stage respectively. Parameters of an inter-stage matching network associated with the first gain stage are configured based on the optimum noise figure and the optimum gain of the first gain stage.
    Type: Application
    Filed: April 18, 2012
    Publication date: October 24, 2013
    Applicant: QUALCOMM ATHEROS INCORPORATED
    Inventor: Celestino A. CORRAL
  • Publication number: 20130222058
    Abstract: An amplifier includes an amplifying element that amplifies an input signal; an output terminal that outputs the signal amplified by the amplifying element; a matching circuit disposed in series between the amplifying element and the output terminal, and performing impedance matching; an impedance converter disposed in series between the amplifying element and the matching circuit or between the matching circuit and the output terminal; and a first resonator and a second resonator connected at the ends of the impedance converter.
    Type: Application
    Filed: January 13, 2013
    Publication date: August 29, 2013
    Inventor: Fujitsu Limited
  • Patent number: 8514017
    Abstract: A variable gain amplifier, to amplify an audio input signal to output an audio output signal at an adjustable gain, includes an operational amplifier having an inverting input terminal, a non-inverting input terminal, and an output terminal to output the audio output signal; an attenuation-rate adjustable feedback circuit to feed back the audio output signal from the output terminal of the operational amplifier to the inverting input terminal of the operational amplifier as a feedback signal, and attenuate the audio output signal and output the feedback signal to the inverting terminal; and an attenuation-rate adjustable attenuator to attenuate the audio input signal for output it as an attenuated signal to the non-inverting input terminal of the operational amplifier. Settings of the attenuation rates of the feedback circuit and the attenuator are combined and a resolution of level of the audio output signal is increased.
    Type: Grant
    Filed: November 8, 2011
    Date of Patent: August 20, 2013
    Assignee: Ricoh Company, Ltd.
    Inventor: Ryuichi Araki
  • Publication number: 20130207725
    Abstract: A passive frequency divider in a CMOS process. More specifically, an electrical distributed parametric oscillator to realize a passive CMOS frequency divider with low phase noise. Instead of using active devices, which are the main sources of noise and power consumption, an oscillation at half of the input frequency is sustained by the parametric process based on nonlinear interaction with the input signal. For example, one embodiment is a 20 GHz frequency divider utilizing a CMOS varactor and made in a 0.13 ?m CMOS process. In this embodiment: (i) without any dc power consumption, 600 mV differential output amplitude can be achieved for an input amplitude of 600 mV; and (ii) the input frequency ranged from 18.5 GHz to 23.5 GHz with varactor tuning. In this embodiment, the output phase noise is almost 6 dB lower than that of the input signal for all offset frequencies up to 1 MHz. Also, a resonant parametric amplifier with a low noise figure (NF) by exploiting the noise squeezing effect.
    Type: Application
    Filed: June 7, 2011
    Publication date: August 15, 2013
    Applicant: CORNELL UNIVERSITY
    Inventors: Ehsan Afshari, Wooram Lee
  • Patent number: 8471630
    Abstract: A fast settling reference voltage buffer and method are disclosed. In one of embodiments, An apparatus comprising: an OTA (operational trans-conductance amplifier) with a positive input terminal coupled to a reference voltage, a negative input terminal coupled to a feedback node, and an output terminal coupled to a circuit node shunt to ground by a shunt capacitor via a current sensor; a tunable resistor, controlled by a control signal, coupling the circuit node to the feedback node; a load circuit coupled to the feedback node via a switch controlled by a logical signal; and a control circuit for receiving an output of the current sensor and outputting the control signal, wherein the control signal is adapted in accordance with the output of the current sensor.
    Type: Grant
    Filed: April 26, 2012
    Date of Patent: June 25, 2013
    Assignee: Realtek Semiconductor Corp.
    Inventor: Chia-Liang Lin
  • Publication number: 20130106507
    Abstract: In accordance with an embodiment of the disclosure, systems and methods are provided for multi-modal power amplification. In certain implementations, an adjustable power amplifier amplifies an input signal, and the amount of amplification is varied based on the input signal. A variable impedance unit receives an amplified input signal, and the amount of load impedance at the variable impedance unit is varied based on the input signal.
    Type: Application
    Filed: October 25, 2012
    Publication date: May 2, 2013
    Applicant: MARVELL WORLD TRADE LTD.
    Inventor: MARVELL WORLD TRADE LTD.
  • Publication number: 20130051582
    Abstract: According to an embodiment, a method includes amplifying a signal provided by a capacitive signal source to form an amplified signal, detecting a peak voltage of the amplified signal, and adjusting a controllable impedance coupled to an output of the capacitive signal source in response to detecting the peak voltage. The controllable impedance is adjusted to a value inversely proportional to the detected peak voltage.
    Type: Application
    Filed: August 25, 2011
    Publication date: February 28, 2013
    Applicant: Infineon Technologies AG
    Inventors: Michael Kropfitsch, Jose Luis Ceballos
  • Publication number: 20130033316
    Abstract: An automatic step variable attenuator includes: a step variable attenuator attenuating a received signal of an electric wave signal in an attenuation amount corresponding to a control signal in a step-like style; a detector disposed in parallel with the step variable attenuator for input of the received signal of the electric wave signal, and converting an electric power of the received signal thus inputted into an intensity signal representing an intensity of the received signal; and a comparator portion generating the control signal corresponding to a result of comparison for differences between the intensity signal obtained from the detector and plural threshold values, and outputting the control signal thus generated to the step variable attenuator.
    Type: Application
    Filed: July 18, 2012
    Publication date: February 7, 2013
    Applicant: Sony Corporation
    Inventors: Noboru Sasho, Naoto Yoshikawa
  • Patent number: 8279002
    Abstract: A variable gain amplifier circuit includes: an operational amplifier having a non-inverting input terminal applied with a predetermined voltage; a feedback resistor having one end connected to an inverting input terminal of the operational amplifier and the other end connected to an output terminal of the operational amplifier; and a variable resistor having one end applied with an input voltage and the other end connected to the inverting input terminal of the operational amplifier.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: October 2, 2012
    Assignees: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.
    Inventors: Takahiro Kawashima, Rui Kurihara
  • Patent number: 8278999
    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.
    Type: Grant
    Filed: January 26, 2011
    Date of Patent: October 2, 2012
    Assignee: Novatek Microelectronics Corp.
    Inventors: Xie-Ren Hsu, Ji-Ting Chen, Yao-Hung Kuo
  • Publication number: 20120200352
    Abstract: An apparatus and method for amplifying a transmission signals in multiple modes and multiple bands. The apparatus includes a tunable power amplifying module adapted to receive a plurality of signal types comprising multiple modes and multiple bands. The tunable power amplifying module includes a first and second power amplifier stages and a number of tunable matching networks configured to optimize an impedance value based on the mode and band of the signal to be amplified.
    Type: Application
    Filed: April 16, 2012
    Publication date: August 9, 2012
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Xu Zhu, Michael L. Brobston, Lup M. Loh
  • Publication number: 20120188011
    Abstract: The embodiments disclosed in the detailed description include a power amplifier having a low power mode amplifier, a medium power mode amplifier, and a high power mode amplifier in communication with a radio frequency (RF) output load. The exemplary embodiments of the power amplifier permit a wireless device to select the most power efficient means to transmit an RF signal based upon the desired output power level.
    Type: Application
    Filed: January 25, 2011
    Publication date: July 26, 2012
    Applicant: RF MICRO DEVICES, INC.
    Inventors: James M. Retz, Ruediger Bauder
  • Publication number: 20120152089
    Abstract: An amplifier for electric guitar including a Cut control for attenuating high frequencies whose operation is expanded via a switch to alternately function as a Master Volume control.
    Type: Application
    Filed: December 21, 2010
    Publication date: June 21, 2012
    Inventor: Randall C. Smith
  • Publication number: 20120112834
    Abstract: A device includes a matching stage coupled between a first signal terminal and a second signal terminal. A signal path extends between the first signal terminal and the second terminal. An adjustable impedance element is connected to the signal path. A detection circuit is coupled to the signal path and configured to derive matching information. A control circuit is coupled between the detection circuit and the adjustable impedance element. The control circuit is configured to control the adjustable impedance element.
    Type: Application
    Filed: January 16, 2012
    Publication date: May 10, 2012
    Applicant: EPCOS AG
    Inventor: Adrianus Van Bezooijen
  • Patent number: 8160518
    Abstract: A transceiver includes a harmonic termination circuit that receives a tunable harmonic voltage from a power amplifier control. The harmonic termination circuit includes a variable capacitor that is capable of adjusting its capacitance in response to the tunable harmonic termination voltage to achieve at least two modes of operation. The at least two modes of operation may be EDGE mode and GSM mode. In this embodiment, the harmonic termination circuit allows for linearity specifications of EDGE to be met, while not degrading the efficiency of the transceiver when operating in GSM mode. In one embodiment, the harmonic termination circuit further includes an inductive element in series with the variable capacitor.
    Type: Grant
    Filed: August 3, 2007
    Date of Patent: April 17, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Marcus R. Ray, Darrell G. Hill, Ricardo A. Uscola
  • Patent number: 8149059
    Abstract: In a method and apparatus for compensating for gain changes in an amplifier circuit comprising radio-frequency modules and attenuation elements, a radio-frequency module is driven with a first temperature-dependent monitoring voltage UHF(T), and an attenuation element with a second temperature-dependent monitoring voltage UVG(T). The first temperature-dependent monitoring voltage UHF(T) is produced by applying a temperature dependency to an individual monitoring voltage Uopt, which is predetermined for a predetermined temperature for a radio-frequency module, in order to set the optimum operating point of the radio-frequency module. The second temperature-dependent monitoring voltage UVG(T) is produced by applying a temperature dependency to a predetermined monitoring voltage UVG—T for the attenuation element. The monitoring voltage UVG—T is determined in an iteration method, such that the output power of the amplifier circuit reaches a predeterminable level at a constant input power.
    Type: Grant
    Filed: March 14, 2009
    Date of Patent: April 3, 2012
    Assignee: EADS Deutschland GmbH
    Inventors: Joerg Schroth, Rolf Reber, Rainer Rittmeyer, Hardy Sledzik
  • Publication number: 20120075016
    Abstract: A calibration unit calibrates a power amplifier load impedance to achieve a nominal amplifier load impedance after the connection of one or more external elements, e.g., antenna, to improve the accuracy and effectiveness of output power calibration. The calibration unit comprises an adaptive impedance unit and a controller. The adaptive impedance unit includes first and second variable impedance elements connected between the amplifier and the external load, e.g., antenna. The controller independently calibrates the imaginary and real parts of the load impedance by respectively selecting first and second calibration values for the first and second variable impedance elements based on a reference voltage. More particularly, the controller selects calibration values for the first and second variable impedance elements from a plurality of impedance values based on a comparison between a reference voltage and the calibrated voltages produced at the output of the power amplifier responsive to the impedance values.
    Type: Application
    Filed: December 30, 2010
    Publication date: March 29, 2012
    Inventors: Hendrik Visser, Roeland Heijna, Norbert Van Den Bos
  • Patent number: 8098094
    Abstract: An input stage for an instrumentation system may include a resistor coupled between an input terminal and a summing node, and an amplifier arranged to maintain the voltage at the summing node. In anther embodiment, an instrumentation input system may include an input stage to receive a signal to be measured, and a variable gain amplifier having an input coupled to an output of the input stage, wherein the variable gain amplifier comprises two or more gain stages. A variable gain amplifier may include an attenuator having an input and a series of tap points and a series of low-inertia switches to steer outputs from the attenuator to an output terminal.
    Type: Grant
    Filed: July 9, 2009
    Date of Patent: January 17, 2012
    Assignee: Analog Devices, Inc.
    Inventor: Barrie Gilbert
  • Publication number: 20110269510
    Abstract: An apparatus and a method for preventing transmission degradation in a mobile terminal. The apparatus includes an antenna, a Power Amplifier Module (PAM), and a matching module. The PAM amplifies power of a transmission signal. A matching module is located between the antenna and the PAM, to match impedance of a signal whose power is amplified by the PAM using a matching value determined depending on a supplied power magnitude of the PAM.
    Type: Application
    Filed: May 3, 2011
    Publication date: November 3, 2011
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventor: Hun-Hee Noh
  • Patent number: 8030996
    Abstract: A circuit and method for automatic level control is provided. The circuit includes an amplifier including a variable resistance circuit that is connected between a first node and a second node. The circuit also includes a first resistance circuit that is connected between a first input node and the first node, and a second resistance circuit that is connected between the first input node and a first op amp node. The first and second resistance circuits are at least approximately linear elements. The circuit also includes an op amp having at least a first input that is connected to the first op amp input node.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: October 4, 2011
    Assignee: National Semiconductor Corporation
    Inventor: Jose Prado
  • Patent number: 7974599
    Abstract: A low noise amplifier includes an input transistor, an inductor, and a current sink. The input transistor includes a gate, a drain, and a source, wherein the gate of the input transistor is operably coupled to receive an input radio frequency (RF) signal. The inductor includes a first node and a second node, wherein the first node of the inductor is operably coupled to a power supply and the second node of the inductor is operably coupled to the drain of the input transistor to provide an output of the low noise amplifier. The current sink includes a first node and a second node, wherein the first node of the current sink is operably coupled to the source of the input transistor and the second node of the current sink is operably coupled to a circuit ground, wherein a real component of input impedance of the low noise amplifier is substantially constant when the low noise amplifier is in the off mode as when the low noise amplifier is in the on mode.
    Type: Grant
    Filed: August 11, 2006
    Date of Patent: July 5, 2011
    Assignee: Broadcom Corporation
    Inventor: Razieh (Rozi) Roufoogaran
  • Publication number: 20110128075
    Abstract: Audio amplifiers are used in many known forms in music systems, for example for domestic use or for playing music in cinemas, discos etc., but also in public address systems, as are known, for example, in public buildings, schools, universities etc. for making announcements. The invention proposes an audio amplifier (1) for amplifying an input signal into an output signal using an output amplifier stage (6), wherein the output amplifier stage (6) is designed to amplify an intermediate signal into the output signal, and wherein the output amplifier stage (6) is in the form of an amplifier which operates in switching mode, and having a limiter device (4) which is designed, from a program and/or circuit point of view, to generate the intermediate signal on the basis of the input signal, wherein the level of the intermediate signal is always limited as a function of an adjustable maximum level in such a way that the output signal does not exceed the maximum level independently of the input signal.
    Type: Application
    Filed: June 10, 2009
    Publication date: June 2, 2011
    Inventors: Martin Maier, Josef Taffner, Josef Plager
  • Publication number: 20110115558
    Abstract: Disclosed herein is a dual band high frequency amplifier using a composite right/left handed (CRLH) transmission line (TL). Accordingly, a CRLH TL structure having a dual band characteristic is inserted into an input matching circuit and/or an output matching circuit in the high frequency amplifier, and a matching circuit is designed so that impedance matching is performed at two frequencies, thereby obtaining both gain and matching characteristics at the two frequencies.
    Type: Application
    Filed: July 9, 2010
    Publication date: May 19, 2011
    Inventors: Jongsik Lim, Dal Ahn
  • Publication number: 20110098013
    Abstract: A high-frequency amplifier includes: an amplification section having a function to convert an input signal from a voltage signal into a current signal and output the current signal; output terminals; and a load circuit which is connected to the output node of the amplification section and outputs the current signal output by the amplification section to the output terminals as a voltage signal.
    Type: Application
    Filed: October 7, 2010
    Publication date: April 28, 2011
    Applicant: Sony Corporation
    Inventors: Katsuaki Takahashi, Noboru Sasho, Naoto Yoshikawa, Taiwa Okanobu