Abstract: Embodiments for at least one method and apparatus of a wireless transceiver are disclosed. For one embodiment, the wireless transceiver includes a transmit chain, wherein the transmit chain includes a power amplifier. The wireless transceiver additionally includes a receiver chain that is tunable to receive wireless signals over at least one of multiple channels, wherein the multiple channels are predefined. Further, the wireless transceiver includes a voltage converter. The voltage converter provides a supply voltage to the power amplifier, and operates at a single switching frequency, wherein the single switching frequency and all harmonics of the single switching frequency fall outside of the multiple channels.

Abstract: A reconfigurable power amplifier includes at least one amplification circuit (E1, E2), and a circuit (6) for controlling the amplification circuit so as to adapt its operation according to an applied input signal (RFin). The circuit for controlling includes a circuit (4, 5) for modifying the compression point of the amplification circuit and for adapting the gain of the amplification circuit in such a manner as to increase the power added efficiency of the circuit for the modified compression point.

Abstract: An amplifying device comprises a first amplifying unit (91-97) capable of changing its gain in a stepwise manner, a second amplifying unit 99 cascade-connected to the first amplifying unit (91-97), the second amplifying unit being capable of changing its gain in a stepwise manner, and a gain controller 100 controls the gain setting of the first amplifying 91-97 unit and the second amplifying unit 99. The first amplifying unit has a gain variable range necessary to amplifying the input signal to the prescribed desired level. The second amplifying unit has a gain variable range narrower than that of the first amplifying unit. When the gain controller changes the gain setting, the gain controller uses the second amplifying unit preferentially over the first amplifying unit.

Abstract: An electronic circuit includes a first variable gain amplifier for amplifying a signal at an input to provide a first amplified signal; a filter receiving the first amplified signal to provide a filtered signal; a second variable gain amplifier for receiving and amplifying the filtered signal; a second gain control bock, to provide at least one gain control signal derived from the filtered signal, one of the at least one gain control signal to control the gain of the second variable gain amplifier; and a bounding block for receiving one of the at least one gain control signal from the second gain control block, and for generating therefrom a bounded gain control signal to control gain of the first variable gain amplifier.

Abstract: Aspects of a method and system for polar modulating QAM signals with discontinuous phase may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain and an amplitude offset gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain. The setting of the coarse amplitude gain and/or said amplitude offset gain may be adjusted dynamically and/or adaptively. The signal may be generated by phase-modulation of a radio-frequency carrier. The combined gain of the plurality of amplifiers may be controlled based on a desired amplitude modulation. The plurality of amplifiers may be integrated within an integrated circuit (IC) or chip.

Abstract: An audio amplifier such as for driving headphones. The amplifier includes multiple amplifier devices coupled in parallel. Both a bias generator and a volume control are responsive to a user setting. Under low output signal conditions, one or more of the amplifier devices are disabled in response to the user setting. Disabled amplifier devices do not consume output bias current. Thus the audio amplifier has reduced power consumption, and the system has longer battery life.

Abstract: A bias circuit 12 includes: a transistor Q5 operable to supply, to an amplifier 11, a bias current in accordance with a base current supplied thereto; a transistor Q3 operable to pass a current in accordance with a reference voltage Vref; a transistor Q2 operable to correct, in accordance with the current passed by the transistor Q3, the base current to be supplied to the transistor Q5, so as to compensate a temperature characteristic represented by the transistor Q5; and a bias changing section (of a transistor Q4, and resistances R5, R6, and R7), connected to a base of the transistor Q5, operable to change, in accordance with a control voltage VSW, an amount of the base current to be supplied to the transistor Q5. The amplifier 11 amplifies, by using the bias current supplied by the bias circuit 12, a radio frequency signal having been inputted thereto.

Abstract: There is provided a modular amplifier structure that includes a plurality of parallel amplifier sub-units. Each amplifier sub-unit is configured to amplify a received payload signal under control of at least one received control signal. Outputs of the amplifier sub-units are applied to a combining circuit. The combining circuit is configured to combine the outputs of the plurality of amplifier sub-units to provide an amplified payload signal.

Abstract: Aspects of a method and system for amplitude calibration for polar modulation with discontinuous phase may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain, an amplitude offset gain and a calibration gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain and the calibration gain. The setting of the coarse amplitude gain, the calibration gain and/or said amplitude offset gain may be adjusted dynamically and/or adaptively.

Abstract: The signal to noise ratio performance of a RF communication system can be improved by providing resistance to transmitter self-jamming and eliminating or reducing the need for a transmit rejection filter or other measures such as limiters or blanking switches. An anti-jam low noise amplifier provides enough rejection and jamming immunity to reduce or eliminate the need for the transmit reject filter. Thus, the system noise performance is improved by eliminating the filter and the associated losses which cause signal to noise ratio performance degradation.

Abstract: A bias control circuit is provided comprising an input port for receiving a signal indicative of an amplitude of a supply voltage provided to a multi stage power amplifier circuit. Electronic circuitry, electrically coupled to the input port, generates a bias control signal in dependence upon the signal indicative of a supply voltage for provision to a first stage power amplifier of the multi stage power amplifier circuit. The bias control signal is generated such that a gain change of the multi stage power amplifier circuit due to a supply voltage change is substantially compensated.

Abstract: A multistage amplifier and design method are disclosed. The multistage amplifier has a plurality of amplifier stages, each stage having an amplifier designed and biased to operate at or near the amplifier's power added efficiency (PAE) peak. The PAE peak of each of the amplifier is at or near the amplifiers linear-compression transition region, providing a multistage power amplifier that is power efficient and has desirable amplitude to amplitude and amplitude to phase power transfer characteristics. The amplifier is designed by matching the output impedance of a final stage with a load. Amplifier stages are iteratively designed from the last stage to the first. At each stage, an amplifier and drive circuit are designed. The drive circuit and amplifier are designed to provide each stage with output impedance matched to the input impedance of the following stage and to operate at or near the PAE peak of the amplifier.

Abstract: The present invention relates to a bias control circuit and method for supplying a bias signal to at least one stage of an amplifier circuit, wherein a dual bias control is provided by generating a bias current and additionally using this bias current to derive a control signal for limiting a supply voltage of the at least one amplifier stage in response to the control signal. Thereby, a compression of the output signal of the amplifier stage, which results from the voltage limitation, can be realized in addition to the base current steering. This leads to a decrease in small signal gain and thus reduced output noise.

Abstract: Techniques for achieving linear monotonic output power with piecewise non-linear and/or non-monotonic circuits are described. A coarse gain is selected for a first circuit having non-linear and/or non-monotonic characteristics. A fine gain is selected for a second circuit used to account for output power error due to the coarse gain. First and second look-up tables may store output power versus gain for the first and second circuits, respectively. An output power in the first look-up table may be selected based on the requested output power, and the gain corresponding to the selected output power may be provided as the coarse gain. An output power in the second look-up table may be selected based on the output power error, and the gain corresponding to the selected output power may be provided as the second gain.

Abstract: Aspects of a method and system for polar modulating OFDM signals with discontinuous phase may include amplifying a normalized OFDM signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain and an amplitude offset gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain adaptively and/or dynamically. The setting of the coarse amplitude gain and/or the amplitude offset gain may be adjusted dynamically and/or adaptively via an amplitude control.

Abstract: A power amplifier subsystem that includes a first stage amplifier and a second stage amplifier. A first bias circuit is coupled to the first stage amplifier, and the first bias circuit has a variable impedance that increases with radio frequency (RF) power. A second bias circuit is coupled to the second stage amplifier, and the second bias circuit has impedance relatively fixed with respect to radio frequency (RF) power. According to an embodiment of the invention, the first bias circuit comprises a transistor having a collector current that increases as radio frequency (RF) power increases. The second bias circuit can have a relatively fixed impedance. A method of designing an amplifier subsystem, where transistor size and resistor values are selected to obtain the desired bias and linearity characteristics, or transistor size and resistor values are selected to operate within a selected range, and amplifier performance is adjusted by changing the bias control voltage.

Abstract: Aspects of a method and system for polar modulating QAM signals with discontinuous phase may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain and an amplitude offset gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain. The setting of the coarse amplitude gain and/or said amplitude offset gain may be adjusted dynamically and/or adaptively. The signal may be generated by phase-modulation of a radio-frequency carrier. The combined gain of the plurality of amplifiers may be controlled based on a desired amplitude modulation. The plurality of amplifiers may be integrated within an integrated circuit (IC) or chip.

Abstract: A post-distortion method for cascading amplifier stages in a two-stage microwave power amplifier and a dynamic biasing method using back-end processing for correcting nonlinearity in the power amplifier output. A first or driver stage biased in a near-A region with low distortion is cascaded with a second or power stage biased in a near-C region with high efficiency. The amplitude and phase responses of the two stages compensate another to yield a more linear overall gain for the overall power amplifier. The dynamic biasing scheme modulates the source to drain voltages of the transistors used in the amplifier stages based on the harmonics in amplifier output in order to minimize the harmonics and correct non-linearity in the output.

Abstract: To provide a bias circuit for gain control that can reduce gain variation at low-power output, facilitate setting of output power, and is unlikely to be affected by variation in element values and variations among products. Use in an HPA having three bias circuits serially-connected is assumed. Current of the third bias circuit is varied with a square-law characteristic. The square-law characteristic is amplified by a buffer amplifier including a linear amplifier and a peripheral circuit thereof. Output current of the third bias circuit varies depending on a current drivability coefficient of the diode-connected FET branched from the connection point between a constant current source and the linear amplifier. The output current of the third bias circuit is controlled by providing a circuit that draws a certain amount of current from the current flowing in the FET.

Abstract: A method for compensating a power amplifier based on operational-based changes begins by measuring one of a plurality of operational parameters of the power amplifier to produce a measured operational parameter. The method continues by comparing the measured operational parameter with a corresponding one of a plurality of desired operational parameter settings. The method continues by, when the comparing of the measured operational parameter with the corresponding one of a plurality of desired operational parameter settings is unfavorable, determining a difference between the measured operational parameter and the corresponding one of a plurality of desired operational parameter settings. The method continues by calibrating the one of the plurality of operational settings based on the difference.

Abstract: Aspects of a method and system for polar modulation with discontinuous phase for RF Transmitters with power control may include performing by one or more circuits comprising a plurality of amplifiers, configuring one or more of the plurality of amplifiers to provide a coarse amplitude gain and a power level gain. One or more remaining ones of the plurality of amplifiers may be configured to provide an amplitude offset gain, and a signal may be amplified utilizing a combined gain provided by the one or more of the plurality of amplifiers and by the one or more remaining ones of the plurality of amplifiers. The signal may comprise modulated RF signal, and/or a phase modulated RF signal. An RF carrier signal may be modulated to generate the signal.

Abstract: An amplifying device comprises a first amplifying unit (91-97) capable of changing its gain in a stepwise manner, a second amplifying unit 99 cascade-connected to the first amplifying unit (91-97), the second amplifying unit being capable of changing its gain in a stepwise manner, and a gain controller 100 controls the gain setting of the first amplifying 91-97 unit and the second amplifying unit 99. The first amplifying unit has a gain variable range necessary to amplifying the input signal to the prescribed desired level. The second amplifying unit has a gain variable range narrower than that of the first amplifying unit. When the gain controller changes the gain setting, the gain controller uses the second amplifying unit preferentially over the first amplifying unit.

Abstract: A broad-band linear amplifier circuit includes a driver amplifier to produce a first amplified radio frequency (RF) signal in a first single RF band in response to a first input RF signal and to produce a second amplified RF signal in a second single RF band in response to a second input RF signal. The first single RF band and the second single RF band reside in a broad band that has a bandwidth more than two times a bandwidth of the first single RF band or the second single RF band. A sensing circuit can sense a power, a gain, or a phase of the first output RF signal and the second output RF signal, and to produce a sensing signal. A gain control circuit controls gain variation of the driver amplifier in response to the sensing signal.

Abstract: This disclosure relates systems and methods for a power amplifier with output power control. The power amplifier can include multiple stages of amplification. An RF signal is fed to the power amplifier with output control that amplifies the power of the RF signal to meet operational requirements. A first stage of the power amplifier controls the output power via voltage regulation. An isolating device is introduced in the transmission path of the RF signal between the first stage and the following stages of the power amplifier. The isolating device ensures that the load impedance of the first stage remains fixed at a constant value.

Abstract: The present invention provides compensation for distortions in a multi-stage amplifier having a gain expansion characteristic. The present invention also provides an approach for using an amplification stage biased in a state close to B-class, which exhibits high power with added efficiency at low output, in order to have a gain expansion characteristic in all stages of a multi-stage amplifier. The amplifier of the present invention has a gain expansion characteristic which presents an increase in gain in response to an increase in input power or output power in a certain range of the input power or the output power.

Abstract: Embodiments of the invention may provide for enhancement systems and methods for a power amplifier output control system. In an example embodiment, driver amplifier control may be provided in conjunction with power amplifier control to improve the power efficiency and/or dynamic range of the transmitter system. Furthermore, control over the driver amplifier may allow for relaxed power control slope, which may lessens the burden of digital to analog converters (DACs) in transmitter systems such as cellular transmitter systems. Also, systems and methods in accordance with example embodiments of the invention may provide a less sensitive solution to operational environment variations such as temperature, battery power voltage and implementation IC process.

Abstract: A linear amplifier circuit includes a first matching circuit that receives a first signal and to produce a first impedance matched signal, a first power amplifier that produces a first amplified signal in response to the first impedance matched signal under the control of a first bias signal, a second power amplifier that produces a second amplified signal in response to the first impedance matched signal under the control of a second bias signal, a biasing circuit that produces the first bias signal and the second bias signal. The first power amplifier can be activated by the first biasing signal when the power of the output signal is to exceed a first threshold value. The second power amplifier can be activated by the second biasing signal when the power of the output signal is below a second threshold value. A second matching circuit configured to receive the first amplified signal and the second amplified signal, and to produce an output signal.

Abstract: Disclosed is a variable gain circuit, which operates in a region where the gain varies substantially exponentially with respect to a control voltage, having an operation region in which the gain varies substantially with an exponential function {(?{square root over (1?x)}??{square root over (2)})2+K}/{(?{square root over (1+x)}??{square root over (2)})2+K} where 0?K?1 and x is a variable corresponding to the control voltage. The denominator and the numerator of the above function are given by a first sum current and a second sum current, respectively. The first sum current is a sum of the drain current of a first transistor and a constant current, and the second sum current is a sum of the drain current of a second transistor and the constant current. The first and second transistors have sources grounded, having gates connected common and supplied with a bias voltage, and having back-gates supplied with control voltages differentially.

Abstract: Disclosed is a direct conversion type transmitter or transceiver circuit suitable for a mobile communication device which corresponds to broad signal output level variable width to be required by W-CDMA, which does not necessitate any high-performance low noise VCO and RF filter, capable of reducing a number of components and the cost. In the input portion of an orthogonal modulator composed of a divider, mixers, and a common load, there are provided variable attenuators. If an input signal level of the orthogonal modulator within the transmitter circuit lowers, this variable attenuator circuit is operated so as to lower the bias of the orthogonal modulator to reduce the amount of occurrence of carrier leak, and to prevent the signal during low output level and carrier leak ratio from being deteriorated.

Abstract: A variable gain amplifier to convert an amplifier input voltage to an amplifier output voltage, the variable gain amplifier includes: a plurality of cascode amplifiers coupled in series; a plurality of switching transistor pair circuits coupled in series; and a bias circuit coupled to provide bias voltages to each of the plurality of cascode amplifiers; wherein each of the switching transistor pair circuits is further coupled between two consecutive ones of the cascode amplifiers; a first one of the cascode amplifiers is configured to receive the amplifier input voltage; and a last one of the cascode amplifiers is configured to provide the amplifier output voltage.

Abstract: A low power consuming mixed mode power amplifier which includes: a low output amplifier circuit generating a power amplified result having high efficiency in a low output mode that is most frequently used; a high output amplifier circuit generating an amplified result having high linearity in a high output mode of a region consuming the most power; and an amplifier controller selectively activating the low and high output amplifier circuits according to a power level of an input signal. The high and low output amplifier circuits have a predetermined gain difference.

Abstract: A tuner down-converts a Radio Frequency (RF) wireless signal and outputs the converted signal. The tuner compensates for a TOP depending on a temperature and: detects a received signal strength depending on a RF output of the tuner and transmitting the detected strength to a gain control unit; measures an operating temperature of the tuner and transmits the measured temperature value; receives the measured temperature value to compare the received temperature value with a reference TOP value, compensating compensates for the TOP value depending on variation in temperature and outputting outputs the compensated value; and receives the compensated value to control the RF output based on the TOP value and the received signal strength.

Abstract: A differential amplifier circuit is connected to the input node and the output node of the final amplification stage through detection circuits. The signal level difference output from the differential amplifier circuit does not change even if the input power varies. Because a change in the power gain at the output node does not travel back to the input node when the load impedance of the wireless frequency power amplifier varies, it is possible to detect only the change in the load impedance. Damage to the final stage can be prevented by controlling the operating current of the final stage and the gain of the drive stage according to the detected load variation. Nonlinear distortion in the wireless frequency power amplifier output can also be reduced by detecting and canceling the change in the gain of the drive stage by changing the gain of the adjustment stage.

Abstract: A power control circuit includes: a fine adjustment variable amplifying unit configured to amplify the input signal in accordance with a first gain set value; a coarse adjustment variable amplifying unit configured to amplify the input signal in accordance with a second gain set value; a branching unit configured to branch an output signal into a feedback signal; a comparing unit configured to compare a gain value between the input signal and the output signal with the required gain set value; a control unit configured to determine the first gain set value and the second gain set value based on the required gain set value; and an adjusting unit configured to adjust the first gain set value and the second gain set value so that the power value of the feedback signal becomes a power value corresponding to the required gain set value.

Abstract: A differential amplifier circuit of simple circuit configuration is disclosed, which is capable of releasing an output signal within a voltage range independent of the voltage range of a differential input signal. The differential amplifier circuit 1 includes: NMOS transistors N1, N2 that constitute a first differential pair configured to input a differential input voltage; a resistor element Ra connected to drain terminals X1, X2 of the NMOS transistors N1, N2; an op-amp OP having input terminals connected to the drain terminals X1, X2; and NMOS transistors N3, N4 that constitute a second differential pair configured to input an output voltage of the op-amp OP and a reference voltage. The drain terminals of the first differential pair are connected to drain terminals, respectively, of the second differential pair.

Abstract: Aspects of a method and system for polar modulating OFDM signals with discontinuous phase may include amplifying an OFDM signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain and an amplitude offset gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain. The setting of the coarse amplitude gain and/or the amplitude offset gain may be adjusted dynamically and/or adaptively.

Abstract: Aspects of a method and system for polar modulating QAM signals with discontinuous phase may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain and an amplitude offset gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain. The setting of the coarse amplitude gain and/or said amplitude offset gain may be adjusted dynamically and/or adaptively. The signal may be generated by phase-modulation of a radio-frequency carrier. The combined gain of the plurality of amplifiers may be controlled based on a desired amplitude modulation. The plurality of amplifiers may be integrated within an integrated circuit (IC) or chip.

Abstract: A bias circuit 12 includes: a transistor Q5 operable to supply, to an amplifier 11, a bias current in accordance with a base current supplied thereto; a transistor Q3 operable to pass a current in accordance with a reference voltage Vref; a transistor Q2 operable to correct, in accordance with the current passed by the transistor Q3, the base current to be supplied to the transistor Q5, so as to compensate a temperature characteristic represented by the transistor Q5; and a bias changing section (of a transistor Q4, and resistances R5, R6, and R7), connected to a base of the transistor Q5, operable to change, in accordance with a control voltage VSW, an amount of the base current to be supplied to the transistor Q5. The amplifier 11 amplifies, by using the bias current supplied by the bias circuit 12, a radio frequency signal having been inputted thereto.

Abstract: According to an exemplary embodiment, a multimode power amplifier configured to receive an RF input signal and provide an RF output signal in linear and saturated operating modes includes an output stage configured to receive a fixed supply voltage and to provide the RF output signal. The multimode power amplifier further includes at least one driver stage coupled to the output stage, where the at least one driver stage is configured to receive the RF input signal and an adjustable supply voltage. The adjustable supply voltage controls an RF output power of the RF output signal when the multimode power amplifier is in the saturated operating mode. The at least one driver and the output stage are each biased by a low impedance voltage in the linear and saturated operating modes. The adjustable supply voltage can be controlled by a fixed control voltage in the linear operating mode.

Abstract: Aspects of a method and system for polar modulating QAM signals with discontinuous phase may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain and an amplitude offset gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain, and a gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain. The setting of the coarse amplitude gain and/or said amplitude offset gain may be adjusted dynamically and/or adaptively. The signal may be generated by phase-modulation of a radio-frequency carrier. The combined gain of the plurality of amplifiers may be controlled based on a desired amplitude modulation. The plurality of amplifiers may be integrated within an integrated circuit (IC) or chip.

Abstract: A multistage amplifier and design method are disclosed. The multistage amplifier has a plurality of amplifier stages, each stage having an amplifier designed and biased to operate at or near the amplifier's power added efficiency (PAE) peak. The PAE peak of each of the amplifier is at or near the amplifiers linear-compression transition region, providing a multistage power amplifier that is power efficient and has desirable amplitude to amplitude and amplitude to phase power transfer characteristics. The amplifier is designed by matching the output impedance of a final stage with a load. Amplifier stages are iteratively designed from the last stage to the first. At each stage, an amplifier and drive circuit are designed. The drive circuit and amplifier are designed to provide each stage with output impedance matched to the input impedance of the following stage and to operate at or near the PAE peak of the amplifier.

Abstract: A linear amplifier circuit includes a first matching circuit that receives a first signal and to produce a first impedance matched signal, a first power amplifier that produces a first amplified signal in response to the first impedance matched signal under the control of a first bias signal, a second power amplifier that produces a second amplified signal in response to the first impedance matched signal under the control of a second bias signal, a biasing circuit that produces the first bias signal and the second bias signal. The first power amplifier can be activated by the first biasing signal when the power of the output signal is to exceed a first threshold value. The second power amplifier can be activated by the second biasing signal when the power of the output signal is below a second threshold value. A second matching circuit configured to receive the first amplified signal and the second amplified signal, and to produce an output signal.

Abstract: A power amplifier subsystem that includes a first stage amplifier and a second stage amplifier. A first bias circuit is coupled to the first stage amplifier, and the first bias circuit has a variable impedance that increases with radio frequency (RF) power. A second bias circuit is coupled to the second stage amplifier, and the second bias circuit has impedance relatively fixed with respect to radio frequency (RF) power. According to an embodiment of the invention, the first bias circuit comprises a transistor having a collector current that increases as radio frequency (RF) power increases. The second bias circuit can have a relatively fixed impedance. A method of designing an amplifier subsystem, where transistor size and resistor values are selected to obtain the desired bias and linearity characteristics, or transistor size and resistor values are selected to operate within a selected range, and amplifier performance is adjusted by changing the bias control voltage.

Abstract: An amplification circuit and scaling method are configured to apply optimum biasing characteristics such that a multistage power amplifier operates according to defined performance characteristics. The operating conditions of the multistage amplifier are optimized by applying independent bias voltages to each stage within the multistage amplifier while operating in a maximum power output range. To achieve optimum or near-optimum operating conditions, each bias voltage is independently scaled according to a specific power output level.

Abstract: The invention is a high-power transconductance circuit (HVTC) comprising three direct-coupled stages which can be substituted for a final-stage power-amplifying vacuum tube in an audio amplifier. The HVTC consists of an input stage, a driver stage, an output stage, and a power conditioner. The input to the HVTC is a composite signal consisting of an AC component and a DC component. The input stage conditions the input composite signal for input to the driver stage. The driver stage transforms the input composite signal into the driving signal for the output stage. The output stage utilizes one or more power transistors to drive a load. The power conditioner supplies regulated power to the HVTC. The input composite signal is direct-coupled through the input stage and the driver stage to the output stage.

Abstract: Aspects of a method and system for polar modulation with discontinuous phase for RF Transmitters with power control may include amplifying a signal via a plurality of amplifiers such that a combined gain of the plurality of amplifiers comprises a coarse amplitude gain, a power level gain and an amplitude offset gain. A gain of one or more of the plurality of amplifiers may be adjusted to set the coarse amplitude gain and the power level gain. A gain of one or more remaining ones of the plurality of amplifiers may be adjusted to set the amplitude offset gain. The setting of the coarse amplitude gain, the power level gain and/or the amplitude offset gain may be adjusted dynamically and/or adaptively.

Abstract: Embodiments of a high-linearity low-noise amplifier (LNA) and method are generally described herein. Other embodiments may be described and claimed. In some embodiments, an RF input signal may be amplified with a cascode amplifier and a common-gate stage. The common-gate stage is dynamically biased based on an output voltage of the common-gate stage to allow an output voltage swing to be shared between the cascode amplifier and the common-gate stage.

Abstract: Power consumed by a power-variable amplifying unit for amplifying and supplying data to an antenna in a mobile telephone carrying out data transmission by changing transmission power in accordance with a TPC bit transmitted from a base transceiver station is reduced. The power-variable amplifying unit is constituted with a variable gain amplifier (21) in which a gain is variably controlled with a control voltage corresponding to the above-described TPC bit, a driver amplifier (22) with a fixed gain, and a power amplifier (23) with a fixed gain. Then, a variable resistance 25 for bypassing a current flowing through a transistor (26) of the driver amplifier (22) is provided, and a resistance value of this variable resistance (25) is variably controlled with the control voltage corresponding to the above-described TPC bit. Accordingly, a current quantity of the current flowing through the transistor 26 can be controlled to be a current quantity according to the control voltage (=transmission power).

Abstract: A buffer amplifier and an associated method have been provided for slew rate and swing level control in the buffering of a signal. The method accepts an input signal having a voltage swing, a swing control signal, and a slew rate control signal. The voltage swing for each output in a set of serially-connected buffer stages is selected in response to the swing control signal. The selected voltage swing for a subset of buffer stages is modified in response to the slew rate control signal. Selecting the voltage swing for each output entails selecting a source current for each buffer stage. A bias current is generated and mirrored through a current source connected to each buffer stage. Modifying the selected voltage swing for each of the subset of buffer stages includes modifying the bias current to the subset of buffer stages.

Abstract: A large amount of user information is transmitted with good efficiency by means of a high-speed downlink by making transmission rates of an uplink circuit and a downlink asymmetrical. The radio communication system includes a plurality of base stations, a plurality of terminals, an uplink established between each of the base stations and each of the terminals for the purpose of radio transmission of prescribed information from a terminal to a base station, and a downlink circuit established between each of the terminals and each of the base station for the purpose of radio transmission of prescribed data from a base station to a terminal.