| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 330086000 |
Variable impedance in feedback path varied by separate control path
| 14 |
| 330103000 |
Multiple feedback paths
| 14 |
| 330084000 |
Plural amplifier channels
| 11 |
| 330098000 |
In cascade amplifiers
| 10 |
| 330109000 |
Frequency responsive feedback means
| 8 |
| 330107000 |
Phase shift means in loop path
| 7 |
| 330096000 |
Combined with control of bias voltage of signal amplifier
| 6 |
| 330110000 |
Nonlinear impedance element in loop path | 5 |
| 20080218259 | Method and apparatus for distortion of audio signals and emulation of vacuum tube amplifiers - A method for digitally processing audio signals to emulate the effects of vacuum tube amplifiers and preamplifiers, musical instrument amplification systems, and distortion effects. By use of a parametrically-controlled non-linear transfer function, non-linear filters, feedback elements, and power-law function models, the dynamic behavior and distortion effects of tube amplification stages are simulated. This provides users with the capability to reproduce the desired sounds of vintage and modern tube amplifier systems and effects with the conveniences and control associated with digital signal processing systems and software. | 09-11-2008 |
| 20090231031 | HIGH-IMPEDANCE LEVEL-SHIFTING AMPLIFIER CAPABLE OF HANDLING INPUT SIGNALS WITH A VOLTAGE MAGNITUDE THAT EXCEEDS A SUPPLY VOLTAGE - A level-shifting amplifier is provided for level-shifting an input signal with a voltage magnitude that exceeds a supply voltage of the amplifier. In operation, the amplifier has an input impedance of greater than 100 MOhms. | 09-17-2009 |
| 20090278598 | METHOD AND APPARATUS FOR MODIFYING INTERACTIONS BETWEEN AN ELECTRICAL GENERATOR AND A NONLINEAR LOAD - A method and apparatus for modifying interactions between an electrical generator and a nonlinear load is described. One illustrative embodiment receives a main control signal at a control input of an engine of the electrical generator, the main control signal controlling at least one of output power, output current, and output voltage delivered by the electrical generator to the nonlinear load, the engine being one of a power amplifier and a converter; measures the impedance of the nonlinear load; and feeds to the electrical generator a compensation signal corresponding to the measured impedance, the compensation signal rendering a transfer function of the output power of the electrical generator with respect to the main control signal substantially insensitive to variations in the impedance of the nonlinear load to stabilize the output power of the electrical generator. | 11-12-2009 |
| 20110032031 | AMPLIFIER CIRCUIT AND LIGHT RECEIVING AMPLIFIER CIRCUIT USING THE SAME - An amplifier circuit includes an amplifier unit that amplifies a signal received by an input terminal and outputs the amplified signal to an output terminal, a feedback capacitor that is connected between the input terminal of the amplifier and the output terminal, and a controller that varies a capacitance in the feedback capacitor for a certain period when a potential of the output terminal in the amplifier unit becomes higher or lower than a certain potential. | 02-10-2011 |
| 20140125407 | BANDWIDTH LIMITING FOR AMPLIFIERS - An apparatus for limiting the bandwidth of an amplifier provides for the design of an input impedance, a feedback impedance, and a load impedance such that the load impedance is proportional to the sum of the input impedance and feedback impedance. A sampling circuit has a load impedance including a resistor and capacitor in series to reduce the effective amplifier transconductance, which decreases bandwidth without increasing noise density or making this circuit more difficult to drive than a conventional circuit. | 05-08-2014 |
| 330085000 |
Amplifier in signal feedback path | 5 |
| 20090058519 | Variable Automatic Limit Control (ALC) Threshold for any Desired Compression Curve - A signal conditioning circuit dynamically adjusts a compression ratio, so as to compress a signal and avoid limiting to the extent possible, thereby avoiding distorting the signal by clipping. An input signal is applied to the input of a programmed gain amplifier (PGA) or other amplifier whose gain can be controlled by a gain control signal. The input or the output of the PGA is sampled by a level detector to produce a level signal that represents the level of the signal. A variable source produces a variable threshold signal. A comparator compares the level signal to the variable threshold signal to produce a difference signal. Control logic generates the gain control signal from the difference signal. When the level signal exceeds the threshold signal, the control logic alters the gain control signal to reduce the gain of the PGA, and when the level signal is less than the threshold signal, the control logic alters the gain control signal to increase the gain of the PGA. The threshold signal varies as a function of the gain control signal. | 03-05-2009 |
| 20120019317 | Self-Oscillating Driver Circuit - A self-oscillating driver circuit includes a driver stage, a feedforward path which is coupled to an input of the driver stage, and a feedback path which couples an output of the driver stage to an input of the feedforward path. The feedforward path includes a feedforward filter which is designed as an active filter. In order to prevent an oscillatory state of the driver circuit at an unwanted frequency, it is proposed that an internal state variable of the feedforward filter be monitored and that the feedforward filter be reset if the value of the monitored internal state variable is outside a predefined range. | 01-26-2012 |
| 20120200350 | RESET AND RESETTABLE CIRCUITS - An amplifier system can include a feedback amplifier circuit having an amplifier, a feedback capacitor connected between an input terminal and an output terminal of the amplifier by at least one first switch, and a reset capacitor connected across the feedback capacitor by at least one second switch and between a pair of reference voltages by at least one third switch. During an input-signal processing phase of operation, a control circuit may close the at least one first switch and open the at least one second switch to electrically connect the feedback capacitor between the input and output terminals to engage feedback processing by the feedback amplifier circuit, and close the third switch to electrically connect the reset capacitor between the first and second voltages to charge the reset capacitor to a selectable voltage difference. During a reset phase of operation, the control circuit may open the at least one third switch, close the at least one second switch and open the at least one first switch to electrically connect the reset capacitor across the feedback capacitor to reset the feedback capacitor using the reset capacitor. The amplifier system can optionally include a plurality of the feedback amplifier circuits. | 08-09-2012 |
| 20120249234 | RECEIVER - A receiver ( | 10-04-2012 |
| 20130187710 | AMPLIFIER CIRCUIT - According to one embodiment, an amplification circuit can be switched between amplifying and calibration modes. During calibration, a preamplifier amplifies a differential input signal and generates a differential output signal. The amplifier circuit includes an input switch unit which sets a differential input signal as the reference voltage signal of the same voltage level at the time of calibration, a PWM conversion unit which carries out Pulse-Width-Modulation of the differential output signal, and generates a differential PWM signal based on the result of comparing the differential output signal with the reference signal, a calibration unit which generates an offset adjustment signal according to the phase difference of differential PWM signals, and an electric amplifier which carries out electric power amplification of the differential PWM signal and generates the differential final output signal. | 07-25-2013 |
| 330112000 |
Positive feedback | 2 |
| 20120105148 | AMPLIFIER CIRCUIT AND RADIO RECEIVER - A feedback resistor is connected between an input terminal and an output terminal of an operational amplifier. A negative resistor is connected between an inverting input terminal and a non-inverting input terminal of the operational amplifier. | 05-03-2012 |
| 20120194269 | PASSIVE AMPLIFIER - A passive amplifier for use with enhanced power supplies, signal preamplifiers and power amplifiers in communications systems particularly in mobile phones, laptop computers and other battery-powered and battery-limited devices. The passive amplifier can be used as an attachment to electric appliances or other power consuming equipment to significantly reduce the electric power requirements of such equipment. These passive amplifiers do not require an outside source of power and can be used to elevate battery power outputs and serve as either low noise signal preamplifiers or transmit power amplifiers for higher performance and extended battery life. Passive amplifier technology is either electromagnetic or dielectric in nature with component parts limited to inductive, capacitive and resistive components. Dielectric amplifier prototypes have gain values in the range of the 10 dB level so as to be useful in communications applications and power amplification. | 08-02-2012 |
| 330105000 |
From impedance in series with output load (e.g., current feedback) | 2 |
| 20120200352 | APPARATUS AND METHOD FOR AN INTEGRATED MULTI-MODE MULTI-BAND POWER AMPLIFIER - 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. | 08-09-2012 |
| 20130076436 | LOAD DETECTING IMPEDANCE MATCHING BUFFER - A buffer amplifier has a power on state and a sleep state. During regular operation a coupling state of a load to an output node is detected using feedback voltage. In a sleep mode and in a power collapse mode a detection current is injected into the output node, to produce a voltage, and the coupling state of the load is detected from the voltage. Optionally, the detection current and detecting of the voltage on the output node is enables by a low duty cycle clock. Optionally, signals generated in detecting the coupling state are qualified through a debounce circuit. | 03-28-2013 |
| 330097000 |
Including D.C. path for signal feedback | 2 |
| 20120200351 | OFFSET CORRECTION CIRCUIT - The present invention quickly detects an offset and prevents cutoff of low frequency signals. Offset detection circuits smooth an output of a variable gain amplifier at a predetermined time constant and detects the offset, which is a DC component. The detected offset is added to the input of the variable gain amplifier by an adder and the offset in the output of the variable gain amplifier is corrected. The time constant in the offset detection circuit is changed by the resistance values of the variable resistors. Then, the time constant is changed to a small time constant when the gain of the variable gain amplifier is changed and thereafter to a large time constant. | 08-09-2012 |
| 20130043943 | GAIN STAGE WITH DC OFFSET COMPENSATION AND METHOD THEREOF - A gain stage with DC offset compensation includes a gain amplifier and a compensation device. The gain amplifier is arranged to amplify an input signal according to a gain control signal. The compensation device is arranged to perform a DC offset compensation applied to the gain amplifier with an operating configuration based on the gain control signal. | 02-21-2013 |
| 330076000 |
Compensating for inter-electrode impedance (e.g., neutralization) | 1 |
| 20120326779 | Amplifier circuit and method for conditioning an output current signal of a detector element - An amplifier circuit comprises a detector element with signal-dependent output current, a load resistance and an operational amplifier. A terminal of the detector element and the load resistance are electrically connected to an input of the operational amplifier. The load resistance is provided in the form of at least two series-connected part-resistors. A compensation capacitor is in each case connected in parallel with each part-resistor, or a number of series-connected part-compensation capacitors are connected in parallel with each part-resistor. The output of the operational amplifier is connected to two of the compensation capacitors or part-compensation capacitors by a feed capacitor so that the effect of a parasitic capacitance of the load resistance is at least partially compensated for. | 12-27-2012 |
| 330102000 |
Current and voltage feedback | 1 |
| 20110140773 | Circuits and Methods for Calibrating Offset in an Amplifier - In one embodiment, the present disclosure includes a circuit comprising an amplifier having an input and an output, an offset detection circuit to detect an offset of the amplifier at the output of the amplifier, and an offset generation circuit having an input coupled to the offset detection circuit and an output coupled to the input of the amplifier to generate an offset at the input of the amplifier during an operational phase of the amplifier based on the detected offset. The generated offset cancels a least a portion of the offset of the amplifier. In one implementation, the amplifier is a sense amplifier in a memory. | 06-16-2011 |
| 330106000 |
In series with input source | 1 |
| 20120119828 | VARIABLE GAIN AMPLIFIER AND AUDIO DEVICE - 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. | 05-17-2012 |
| 330087000 |
Cathode impedance feedback | 1 |
| 20220140791 | Load Regulation for LDO with Low Loop Gain - Circuits and methods for maintaining loop stability and good load regulation in low loop gain LDO regulator circuits. Embodiments encompass LDO regulator circuits that include an offset error correction circuit that generates an opposing voltage V | 05-05-2022 |
| Entries |
| Document | Title | Date |
|---|
| 20080224772 | Operational Amplifier Selecting One of Inputs, and an Amplifying Apparatus Using the Op Amplifier the Verification Method - A current feedback-type operational amplifier comprising multiple input parts and one output part, wherein each of the multiple input parts comprises a first input terminal, a second input terminal, and an output terminal, the signals input from the first input terminal are buffer amplified and output to the second input terminal, and current is output to the output terminal in an amount corresponding to the current that flows to the second input terminal; the output terminal part comprises an input terminal and an output terminal, signals obtained by adding in terms of current the signals of all of the input parts are input to the input terminal, and the signals input to the input terminal are converted to voltage signals, amplified, and output to the output terminal; and one of the above-mentioned input parts is made effective and the other input parts are made ineffective in response to first external signals, the impedance of the first input terminal, the second input terminal, and the output terminal of the above-mentioned ineffective input parts becomes high and the output current from the above-mentioned output terminal becomes zero. | 09-18-2008 |
| 20090085657 | COMPENSATION OF FIELD EFFECT ON POLYCRYSTALLINE RESISTORS - 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. | 04-02-2009 |
| 20090267688 | COMBINED FEEDBACK AND FEED-FORWARD LINEARIZATION OF RF POWER AMPLIFIERS - A power amplifier module and corresponding system are disclosed for linearizing the output from a power amplifier. Both a feedback system, containing a compensator and the power amplifier in a feedback loop, and a pre-distortion compensation system injecting pre-distortion signals into or before the feedback system are used to compensate for non-linearities in the overall system. The pre-distortion signals may be mixed with signals from the compensator or may be filtered to take into account the loop compensator transfer function of the feedback loop, mixed with baseband signals and then converted into analog signals that are provided to the feedback loop. In modules containing a tracking power supply, an envelope calculator calculates an RF envelope of the baseband signals, which the pre-distortion system uses in conjunction with the baseband signals to generate the pre-distortion signals mixed with the signals from the compensator. | 10-29-2009 |
| 20100127772 | FEEDBACK AMPLIFIER AND AUDIO SYSTEM THEREROF - A feedback amplifier includes an operational amplifier having an input end and an output end. A first resistor is coupled with the input end of the operational amplifier. A second resistor has a first end coupled with the input end of the operational amplifier and a second end coupled with the output end of the amplifier. A voltage divider has a first end being operably coupled with the output end of the operational amplifier and a second end being analog grounded. In an embodiment, the feedback amplifier further includes a first switch coupled to the first end of the voltage divider and the output end of the operational amplifier, and a second switch coupled to an internal node of the voltage divider. In an embodiment, the feedback amplifier is configured to provide attenuation when the first switch is open and second switch is closed. | 05-27-2010 |
| 20100164617 | DYNAMIC SIGNAL CONTAMINATION SUPPRESSION - A self-configurable amplifier and method of amplification, including an RF signal level detector having an input connected to an RF signal, and an output configured to produce a control signal responsive to a power level of the RF signal. The control signal is supplied to a parametric adjustment circuit that includes an input connected to the control signal, and an output configured to provide a negative feedback responsive to the control signal. The negative feedback is supplied to an RF amplifier that includes an input forming an input of the self-configurable amplifier, an output forming an output of the self-configurable amplifier, and a control port connected to the output of the parametric adjustment circuit, such that one or more parameters of the RF amplifier is responsive to the negative feedback. | 07-01-2010 |
| 20110068863 | Area Efficient, Programmable-Gain Amplifier - 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. | 03-24-2011 |
| 20110074502 | MULTIPLE-INPUT AND MULTIPLE-OUTPUT AMPLIFIER HAVING PSEUDO-DIFFERENTIAL INPUTS - 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. | 03-31-2011 |
| 20110133832 | DIGITAL AMPLIFIER WITH FEEDFORWARD AND FEEDBACK CONTROL - The invention relates to a digital amplifier for providing a desired electrical output power, the amplifier comprising a power source ( | 06-09-2011 |
| 20110163802 | Amplifier Arrangement and Method for Signal Amplification - 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 (E | 07-07-2011 |
| 20110204972 | AMPLIFYING CIRCUIT - 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 ( | 08-25-2011 |
| 20110241771 | ACTIVE MUTE SCHEME FOR AN AMPLIFIER - 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. | 10-06-2011 |
| 20120001687 | RECEIVING APPARATUS AND AUTO GAIN CONTROL METHOD - 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 ( | 01-05-2012 |
| 20120044019 | POWER AMPLIFIER - Power amplifier for amplifying an electric input signal in an operational frequency range and providing an output signal, comprising switching means ( | 02-23-2012 |
| 20120075015 | Amplifier and method for linearizing same - An amplifier circuit and method are described for linearizing the gain of a voltage or current feedback amplifier that is non-linear. | 03-29-2012 |
| 20120249233 | ADAPTIVE DIGITAL PRE-DISTORTION METHOD AND DEVICE TO ENHANCE THE POWER UTILITY OF POWER AMPLIFIERS IN WIRELESS DIGITAL COMMUNICATION APPLICATIONS - 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. It describes a method for linearizing a power amplifier circuit having a digital base-band input signal, a power output signal, a power amplifier and a linearizer module (LM), this method comprising the steps of: extracting a feedback signal from the power amplifier (PA) output signal, down-converting the feedback RF-signal to feedback IF-signal, filtering the feedback IF-signal with a band-pass filter, A/D converting the filtered feedback IF-signal into a feedback digital signal, converting the feedback digital signal into frequency-domain using fast-Fourier transform FFT on a block of n-samples to obtain a feedback FB-FFT block, converting the input base-band digital signal into frequency-domain using fast-Fourier transform FFT on a block of n-samples to obtain a input FF-FFT block, dividing the input FF-FFT block with the feedback FB-FFT block to obtain FFT correction samples blocks, averaging at least two blocks of FFT correction samples to obtain FFT correction coefficient values, applying the FFT correction coefficient values to a digital complex multiplier, converting the output of the multiplier from frequency domain into time domain with an inverse FFT module to obtain a corrected digital input signal, converting the corrected digital input signal to analog IF signal with a digital to analog converter to obtain a corrected IF input signal, applying the band-pass filter to the corrected IF input signal, up-converting the filtered corrected IF input signal to obtain a corrected RF input signal, applying the corrected RF input signal to the power amplifier. | 10-04-2012 |
| 20120293250 | AMPLIFIER - 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. | 11-22-2012 |
| 20120319770 | Output Buffer Circuit Capable of Enhancing Stability - 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. | 12-20-2012 |
| 20130057340 | POWER SUPPLY DEVICE AND POWER AMPLIFICATION APPARATUS USING SAME - 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. | 03-07-2013 |
| 20130069719 | AMPLIFIER CIRCUIT, DETECTOR ARRANGEMENT AND METHOD FOR OPERATING AN AMPLIFIER - An amplifier circuit comprises a measurement path with an amplifier ( | 03-21-2013 |
| 20130088291 | COMBINED FILTER AND TRANSCONDUCTANCE AMPLIFIER - 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. | 04-11-2013 |
| 20130120059 | AMPLIFIER CIRCUIT AND LIGHT RECEIVING CIRCUIT - 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. | 05-16-2013 |
| 20130162348 | ADAPTIVE PREDISTORTION FOR A NON-LINEAR SUBSYSTEM BASED ON A MODEL AS A CONCATENATION OF A NON-LINEAR MODEL FOLLOWED BY A LINEAR MODEL - 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. | 06-27-2013 |
| 20130162349 | Look-Up-Table Digital Predistortion Technique for High-Voltage Power Amplifiers in Ultrasonic Applications - 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. | 06-27-2013 |
| 20130214856 | SWITCHING AMPLIFIER SYSTEM AND METHOD FOR SUPPRESSING SIGNAL DISTORTION THEREOF - 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. | 08-22-2013 |
| 20130222055 | Feedback Control And Coherency Of Multiple Power Supplies In Radio Frequency Power Delivery Systems For Pulsed Mode Schemes in Thin Film Processing - 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. | 08-29-2013 |
| 20140203868 | COMMUNICATIONS BASED ADJUSTMENTS OF A PARALLEL AMPLIFIER POWER SUPPLY - 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. | 07-24-2014 |
| 20140203869 | COMMUNICATIONS BASED ADJUSTMENTS OF AN OFFSET CAPACITIVE VOLTAGE - 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. | 07-24-2014 |
| 20140266422 | DC Blocker for a High Gain Complex Circuit - 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. | 09-18-2014 |
| 20140266423 | Envelope Tracking System with Internal Power Amplifier Characterization - 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. | 09-18-2014 |
| 20140285260 | Output Buffer Circuit Capable of Enhancing Stability - 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. | 09-25-2014 |
| 20150091642 | METHOD AND CIRCUITRY FOR MULTI-STAGE AMPLIFICATION - 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. | 04-02-2015 |
| 20150333710 | HIGH EFFICIENCY LINEARIZATION POWER AMPLIFIER FOR WIRELESS COMMUNICATION - A predistortion system for linearizing the output of a power amplifier includes a first signal representative of an RF modulated signal and a feedback signal representative of nonlinear characteristics of a power amplifier. The system also includes a predistortion controller, comprising at least one lookup table, adapted to receive the first signal and the feedback signal and to generate a correction factor for correcting the nonlinear characteristics of the power amplifier and combining logic which combines the RF modulated signal with a signal corresponding to the correction factor and supplies it to the power amplifier to linearize the output of the power amplifier. | 11-19-2015 |
| 20160065147 | RECEIVERS FOR DIGITAL PREDISTORTION - Aspects of this disclosure relate to a receiver for digital predistortion (DPD). The receiver includes an analog-to-digital converter (ADC) having a sampling rate that is lower than a signal bandwidth of an output of a circuit having an input that is predistorted by DPD. DPD can be updated based on feedback from the receiver. According to certain embodiments, the receiver can be a narrowband receiver configured to observe sub-bands of the signal bandwidth. In some other embodiments, the receiver can include a sub-Nyquist ADC. | 03-03-2016 |
| 20160079933 | BASEBAND EQUIVALENT VOLTERRA SERIES FOR DIGITAL PREDISTORTION IN MULTI-BAND POWER AMPLIFIERS - Methods, systems and apparatus for modelling a power amplifier and pre-distorter fed by a multi-band signal are disclosed. According to one aspect, a method includes receiving a multi-band signal and generating a discrete base band equivalent, BBE, Volterra series based on the received multi-band signal, where the series has distortion products grouped according to determined shared kernels. The shared kernels are determined based on a transformation of a real-valued continuous-time pass band Volterra series without pruning of kernels. | 03-17-2016 |
