Amplifiers inventions 07/06

20060164162 - Low noise variable gain amplifier: The present invention provides systems and methods for asymmetrically varying gain in a low noise amplifier. The amplifier includes a first stage amplifier, a plurality of second stage amplifiers coupled to the first stage amplifier, a comparator coupled to one of the second stage amplifiers, and a controller coupled to...

20060164163 - Amplifiers with high efficiency in multiple power modes: Described herein are representative embodiments of amplifiers having selectable power output while maintaining low power consumption. In certain exemplary embodiments, the amplifiers are operated as linear power amplifiers, such as may be used in wireless communication systems. According to one exemplary embodiment, a circuit is described comprising a control system...

20060164164 - Variable gain amplifier with low phase variation: A VGA is provided that is designed to reduce or even eliminate entirely variations in phase response/shift with changes in gain. Compensation is made for parasitic capacitances of elements in the VGA that would otherwise cause variation in phase with changes in gain. An additional capacitance is introduced to the...

20060164165 - Amplifier output voltage swing extender circuit and method: An amplifier output voltage swing extender circuit comprises a differential amplifier powered between first and second power supply rails, which receives first and second input signals at non-inverting and inverting inputs, respectively, and provides an output at a first output node. A level shifting circuit, preferably a voltage divider, is...

20060164166 - Silicon-on-insulator differential amplifier circuit: A differential amplifier formed on a silicon-on-insulator substrate, including means to prevent the bodies of its differential input transistors from charging to unwanted potentials in the standby state. In one aspect of the invention, the means takes the form of switching transistors inserted between the differential input transistors and their...

20060164167 - Linear commutating amplifier: An amplifier compensates for inherent non-linearities in its open loop behavior by using a first amplification stage configured as a voltage follower to follow an input voltage, which produces a signal that corresponds to the inverse of the non-linear transfer characteristic of the open loop amplifier used within that first...

20060164168 - Power amplifier circuit and method thereof: A power amplifier circuit amplifying an input signal to an output signal and a method thereof. The power amplifier circuit comprises a ramp controller, a current source, and a first amplification stage. The ramp controller receives an enable signal to generate a ramp signal. The current source is coupled to...

20060164169 - Power distribution and biasing in rf switch-mode power amplifiers: Methods of and apparatus for distributing power and biasing RF PAs. A power distribution network includes a pre-final amplifier stage power distribution network and a final amplifier stage power distribution network. The pre-final amplifier stage power distribution network includes one or more pre-final amplifier stage power distribution branches, which may...

20060164170 - Small signal amplifier with large signal output boost stage: A small signal amplifier with a large signal output boost stage are connected between first and second supply rails. The small signal amplifier receives first and second input signals and provides an output signal at an output node which drives a load. Under small signal conditions, the output signal varies...

20060164171 - Method for transforming output signals of a low-noise amplifier of a wireless transceiver: A method for transforming single-ended signals outputted from a low-noise amplifier of a wireless transceiver into differential signals. The method includes: providing a transformer according to a default requirement of the wireless transceiver; transferring the single-ended signals provided by the low-noise amplifier to a first end of a primary end...

20060164172 - Radiofrequency amplifier device, in particular for cellular mobile telephone: A radiofrequency amplifier device includes a transconductor stage having an input for receiving a radiofrequency signal, and a cascode stage connected to the output of the transconductor stage. The device also includes an auxiliary radiofrequency amplifier compensation stage connected as a negative-feedback loop between the output of the transconductor stage...

20060158244 - Circuits and methods for minimizing chopping artifacts at the output of a chopper-stabilized operational amplifier: An operational amplifier including at least one amplifier stage and chopping circuitry for chopping an input signal to the amplifier stage and an output signal from the chopping signal having a frequency randomly varying within the selected frequency band....

20060158248 - Dynamic pulse width modulation amplifiers: A dynamic pulse width modulation (PWM) amplifier comprising an input terminal, a dynamic PWM controller, a power stage, a low pass filter, and an output terminal. The input terminal receives an input signal. The dynamic PWM controller transforms the N-bit input signal sampled by a sampling frequency to a 1-bit...

20060158246 - Pwm digital amplifier with high-order loop filter: An improved PWM amplifier is disclosed that uses multiple integrators in the loop filter to provide high loop gain across the frequency band-of-interest. The frequency characteristics of the loop filter are optimized to distribute large loop gains across the entire band to provide large suppression of noise and distortions generated...

20060158247 - Pwm digital amplifier with high-order loop filter: An improved PWM amplifier is disclosed that uses multiple integrators in the loop filter to provide high loop gain across the frequency band-of-interest. The frequency characteristics of the loop filter are optimized to distribute large loop gains across the entire band to provide large suppression of noise and distortions generated...

20060158245 - Pwm power amplifier and method for controlling the same: The present invention provides a PWM power amplifier and a method for controlling the same which can improve the sound quality significantly in real time. There is provided a PWM power amplifier and a method for controlling the same that PWM-power-amplifies an input audio signal to supply thus amplified audio...

20060158249 - Linear amplifier and schmitt trigger using an analogue switch: A linear amplifier has an input terminal and an analogue switch. A switch input is connected to the input terminal and a switch output is connected to the switch input to provide negative feedback. The switch output may be connected to an output terminal. The switch may also be connected...

20060158250 - Multi-band power amplifier module for wireless communication devices: A multi-band power amplifier module includes a first power amplifier that amplifies a first input radio frequency signal in a first frequency band in response to a first bias control signal. A second power amplifier amplifies a second input radio frequency signal in a second frequency band in response to...

20060158252 - Multi-band power amplifier module for wireless communication devices: A multi-band power amplifier module includes a first power amplifier that amplifies a first input radio frequency signal in a first frequency band in response to a first bias control signal. A second power amplifier amplifies a second input radio frequency signal in a second frequency band in response to...

20060158253 - Multi-band power amplifier module for wireless communication devices: A multi-band power amplifier module includes a first power amplifier that amplifies a first input radio frequency signal in a first frequency band in response to a first bias control signal. A second power amplifier amplifies a second input radio frequency signal in a second frequency band in response to...

20060158251 - Multi-band power amplifier module for wireless communications: A multi-band power amplifier module includes a first power amplifier that amplifies a first input radio frequency signal in a first frequency band in response to a first bias control signal. A second power amplifier amplifies a second input radio frequency signal in a second frequency band in response to...

20060158255 - Adaptive predistortion for a transmit system with gain, phase and delay adjustments: Systems and methods relating to the provision of gain, phase and delay adjustments to signals to be used by a predistortion subsystem. A portion of an input signal is delayed by delay elements prior to being received by the predistortion subsystem. The delayed input signal portion is also received by...

20060158254 - Efficient method and means for integration of power control and predistortion in a transmitter: A radio-frequency (RF) transmitter power amplifier circuit provides for practically linear performance by predistorting the amplifier input signals to compensate for amplifier distortion at high power levels, and provides a fine degree of control of amplifier power needed to handle complex modulation schemes with widely and rapidly varying power requirements....

20060158256 - Amplifier circuit having an extended wilson current-mirror self-bias boosting circuit: An amplifier circuit (1) includes an amplifying transistor (QO) and a do bias circuit (2) for biasing the amplifier transistor (QO) to obtain a conduction angle of at least about 180°. The do bias circuit (2) includes a self-bias boosting circuit which has a Wilson current-mirror (Q4, Q5, Q6) integrated...

20060158257 - Semiconductor circuit: Second transistors working as temperature-monitoring elements are disposed in the vicinity of the respective first transistors (HBT cells) connected in parallel to amplify an RF signal and at positions where their thermal environments are substantially the same. Each of the second transistors is connected between its collector and its base...

20060158258 - Balanced single ended to differential signal converter: Techniques and circuits for generating a pair of differential signals with balanced switching between logical states from a single ended input signal are provided. The differential signals may be generated by controlling the switching of substantially identical driver stages with a set of control signals generated based on the single...

20060152278 - Apparatus for controlling modulation of an alternating waveform on a dc voltage signal within a low-noise block controller: An apparatus for controlling modulation of an alternating waveform on a direct current (DC) voltage signal within a low-noise block (LNB) controller is disclosed. The apparatus includes a DC power supply and a mixing/switching circuit. The DC power supply provides a steady DC voltage to a load, such as an...

20060152277 - Pulse modulated power converter: A pulse modulation power converter comprising a forward path including a forward block (15), a switching stage (11) for amplifying an output from the forward block, and an output filter (12) for low pass filtering an output signal from the switching stage, a global feedback path (13), connected to the...

20060152279 - Doherty microwave amplifier and signal processing method thereof: A Doherty microwave amplifier having a main amplifier and a peaking amplifier, distributing and inputting an input signal to the main amplifier and the peaking amplifier to obtain an output signal by combining an output from the main amplifier and an output from the peaking amplifier, comprises a first coupler...

20060152280 - Systems, methods and devices for differential active bias of multi-stage amplifiers: Systems, devices, and methods are provided for actively biasing a multi-stage amplifier. A method for differentially actively biasing a multi-stage amplifier comprises the steps of: actively biasing, with a single active bias circuit, an amplifier comprising a plurality of amplification stages; and differentially applying the bias provided by the single...

20060152281 - Class-d amplifier with noise-immunity feedback: A class-D amplifier includes a switching transistor section, a filter, an analog to digital converter, and a feedback module. The switching transistor section is operably coupled to convert a serial input into a switched output signal. The filter is operably coupled to filter the switched output signal to produce an...

20060152283 - Circuit and method for avoiding circuit performance degradation caused by time-variable thermal imbalances: A signal processing circuit includes a circuit stage for operating on signals in a signal path of an input signal, including main circuitry for operating on relatively small-value signals and alternative circuitry for amplifying/processing signals during a condition which otherwise would cause thermal imbalance in the main circuitry. The circuit...

20060152282 - Differential amplifier circuit and method for reducing thermally induced offsets caused by large differential signals: An amplifier includes a differential amplifier (10) having an input stage (20) for amplifying a differential input signal (Vin), and an output stage (6) coupled to the input stage (20) for producing and output signal (Vout). The input stage (20) includes main input circuitry (20A) for amplifying small-signal values of...

20060152284 - Semiconductor device with high-breakdown-voltage regulator: A semiconductor device comprises a high-breakdown-voltage regulator (11) configured to operate at a high input voltage (V1); a reference voltage generating circuit structured as a low-breakdown-voltage component and configured to receive an output voltage from the high-breakdown-voltage regulator to generate a reference voltage VREF2; a differential amplifier circuit (M5) structured...

20060152285 - Continuos alternating closed-open loop power control: The present invention comprises a method and apparatus for continuously, controlling a gain of an amplifier circuit while switching between open-loop and closed-loop power control. A control circuit controls the gain of the amplifier circuit during open-loop and closed-loop power control modes based on selected references. Before the switch from...

20060152286 - High-frequency amplifier: A high frequency amplifier includes a constant voltage driven amplifier 1 using as its amplifying element a bipolar transistor 7 with its base biased by a constant voltage, and a constant current driven amplifier 2 using as its amplifying element a bipolar transistor 8 with its base biased by a...

20060152287 - Bias compensation circuit for rf power amplifier: An electronic circuit contains a controller integrated circuit and a power amplifier MMIC connected to the controller IC. The power amplifier MMIC contains a radio frequency power amplifier. The RF power amplifier is a double heterojunction bipolar transistor. The controller IC has an operational amplifier that supplies a DC bias...

20060152288 - Method and system for amplifying a signal: According to one embodiment of the invention, an amplifier includes a gate bias circuit operable to generate a gate bias voltage and a common gate amplifier that includes a transistor having a gate biased by an output of the gate bias circuit and also having a source connected to an...

20060145756 - Apparatus and method for processing description information of multimedia data: In an apparatus and a method for processing description information of multimedia data, in order to reflect a user's preference about multimedia data, a usage history of a user is made by adding description information to the multimedia data, in order to manage the usage history efficiently the apparatus includes,...

20060145755 - Square wave modulation design for a class-d audio amplifier: The present invention provides a square wave modulation design to control the frequency and phase of the carrier for a Class-D audio amplifier. In a half bridge-tied mode, the Class-D audio amplifier comprises a PWM (Pulse Width Modulator) for receiving an input signal and a square wave, a predriver and...

20060145757 - Power amplifying apparatus using asymmetric power drive: A power amplifying apparatus includes a Doherty amplifier having a carrier amplifier and a peaking amplifier connected in parallel, each having an input/output matching circuit and an asymmetric power driver for driving the carrier amplifier and the peaking amplifier using an asymmetric power driver....

20060145758 - Multi-state load switched power amplifier for polar modulation transmitter: A polar modulation power amplifier circuit includes a control circuit (101) to determine and provide a load selection signal (127), wherein the load selection signal (127) is determined responsive to a requested power signal (119). A power amplifier (113) is responsive to a power control signal (141), for amplifying an...

20060145760 - High efficiency linear rf amplifier: An amplifier comprises a first transistor for providing signal amplification, and a second transistor for providing distortion compensation, wherein said second transistor is capable of simultaneously providing more than one form of distortion compensation. A first signal path passes through a first transistor to provide signal gain, and a second...

20060145759 - Method for improving the output power of a non-linear power amplifier: A method for improving the output power of a non-linear amplifier, wherein signal amplitudes of a digital baseband are predistorted and then fed at the input of the power amplifier, having a non-linear characteristic curve, in order to linearize the characteristic curve. The signal amplitudes are fed to the input...

20060145761 - High efficiency switch-mode power amplifier: A switch mode power amplifier includes a transistor responsive to input signals above 1.0 GHz and which includes one terminal coupled to ground and another terminal conductively coupled to a power source. A resonant circuit coupled the second terminal to an output with a resistive load coupled across the output...

20060145762 - Gain boosting for tuned differential lc circuits: A gain boost circuit and methodology are described for providing improved gain boosting with tuned amplifier circuits, such as differential low noise amplifier circuits having output resonant tank circuits. By selectively controlling the current source for a negative transconductance stage coupled between the differential amplifier output and the output resonant...

20060145763 - Low voltage class ab transconductor circuits: A class AB transconductor circuit comprises complementary PMOS and NMOS transistors (10, 12) having their source-drain paths connected in series between first and second voltage supply rails (14, 16). An output terminal (20) is coupled to a junction of said series connected source-drain paths. Gate electrodes of the PMOS and...

20060145764 - Power control circuit and method: A method (400) for controlling power and an amplifier and associated power control circuit (100) with a power amplifier (110) coupled through a current sensing resistor (Rsen) to a supply voltage line (vcc). There is also a current to voltage converter (120) having a converter output (135) and at least...

20060145765 - Bias circuit: A bias circuit includes a voltage stabilizer connected between a control voltage input terminal through a current limit resistor and a ground, a bias supply emitter follower with a base connected to a node between the current limit resistor and the voltage stabilizer through a resistor, and a current limiter...

20060145766 - Power amplifier with bias control: A power amplifier (100) suitable for use in mobile telecommunications equipment has a first stage (2) and an optional second stage (2), each stage being provided with a bias circuit (4, 5). To provide a well-defined gain characteristic, in the first stage (1) a bias current (Ib1) is fed into...