Abstract: An amplifier arrangement with an amplifier arrangement input and an amplifier arrangement output is disclosed. The amplifier arrangement comprises a first transistor and a first ballast resistance, wherein the first ballast resistance connects a first transistor base of the first transistor to a common base terminal at least one second transistor and at least one second ballast resistance, wherein the at least one second ballast resistance connects a second transistor base of the at least second transistor to the common base terminal; and a feedback device comprising a feedback input terminal for sensing at least a base voltage of the first transistor and further comprising a feedback output terminal that is connected to the common base terminal.

Abstract: Disclosed is a 3-way Doherty power amplifier using a driving amplifier in which driving amplifiers are connected to the front stages of a carrier amplifier and a peaking amplifier, respectively, so as to obtain a high gain and a high efficiency. To this end, the Doherty power amplifier includes: a hybrid power distributor for distributing an input signal into first and second path units; and a driving amplifier for receiving a signal outputted from the hybrid power distributor and controlling the driving of a carrier amplifier, a first peaking amplifier, and a second peaking amplifier, wherein: the carrier amplifier, the first peaking amplifier, and the second peaking amplifier are connected to a rear stage of the driving amplifier, respectively; the first path unit generates a high efficiency at a low input power; and the second path unit maintains a high efficiency and gain in a high output range.

Abstract: Disclosed is a matrix distributed amplifier (DA) having an input transmission line, an intermediate transmission line, and an output transmission line. A first plurality of amplifiers has inputs coupled to and spaced along the input transmission line and has outputs coupled to and spaced along the intermediate transmission line. A second plurality of amplifiers has inputs coupled to and spaced along the intermediate transmission line and has outputs coupled to and spaced along the output transmission line. A termination amplifier has an input coupled to the input transmission line and an output coupled to the intermediate transmission line. In at least one embodiment, a second termination amplifier has an input coupled to the intermediate transmission line and an output coupled to the output transmission line.

Abstract: A dual band amplifier is provided comprising a first matching circuit disposed in a first radiofrequency path between an input port and a first amplifier and a second matching circuit disposed in a second radiofrequency path between the input port and a second amplifier. The first matching circuit transforms a first input impedance of the first amplifier to a predetermined input port impedance when the radiofrequency signal is in a first frequency range and transmits the first input impedance to the input port when the radiofrequency signal is in the second frequency range. The second matching circuit transforms the second input impedance to the input port impedance when the input signal is in the second frequency range and transmits the second input impedance to the input port when the radiofrequency signal is in the first frequency range.

Abstract: A Doherty amplifier includes a carrier amplifier including a first FET, the first FET having a plurality of gate electrodes, and a peaking amplifier including a second FET, the second FET having a plurality of gate electrodes, a gate-to-gate interval of the gate electrodes of the second FET being shorter than a gate-to-gate interval of the first FET.

Abstract: A Doherty amplifier includes a first amplifier, a second amplifier, a transmission line, a synthesizer, and an output load. The first amplifier amplifies an RF input signal according to a voltage applied to a supply terminal thereof. The second amplifier amplifies a peak component of the RF input signal according to a voltage applied to a supply terminal thereof. The transmission line is coupled to an output terminal of the first amplifier. The synthesizer is coupled to an output terminal of the transmission line and an output terminal of the second amplifier. It is set such that the voltage applied to the supply terminal of the first amplifier is lower than the voltage applied to the supply terminal of the second amplifier, and that an impedance value of the transmission line is smaller than a value twice an impedance value of the output load.

Abstract: The present invention relates to a power supply control network of an amplifying active elements system enabling at least one control signal to be transmitted to N different control systems of the power supply voltage of P different composed active amplifying elements. It comprises a set of distributor elements of power supply control signals connected in cascade.

Abstract: The invention refers to a Doherty power amplifier comprising a first power amplifier (Main PA) adapted to receive an input signal and adapted to provide a first output signal which is phase shifted with respect to the input signal. The amplifier further comprises a second power amplifier (Peak PA), adapted to receive a phase shifted input signal and adapted to provide a second output signal. The power amplifier is characterized in that at least one of the first or the second power amplifiers comprises a first driver power amplifier (T1) comprising a first gate input and a first drain output. The first driver power amplifier (T1) is coupled to a first output power amplifier (T2) comprising a second gate input and a second drain output. The first gate input and the second gate input are adapted to receive a control signal, the control signal being obtained after an envelope detection provided by an envelope detector coupled to the input signal.

Abstract: A feedforward linearizer device is disclosed. The device includes a main amplifier, and a linearizing amplifier operatively coupled to the main amplifier. A first reference generator is operatively coupled to the main amplifier by a first reference node. A second reference generator is operatively coupled to the linearizing amplifier by a second reference node, and is configured to cause an optimal linearizing amplifier output current for each of a plurality of temperatures. In one such case, the second reference generator is configured to cause an optimal linearizing amplifier output current for each of a plurality of temperatures based on a corresponding optimal ratio of main amplifier output current and linearizing amplifier output current. The linearizing amplifier may be configured with a tunable current source that is controlled by the second reference generator, or a current source having a fixed total transistor area (not tunable).

Abstract: The present invention relates to a composite amplifier (3, 4, 120), a radio terminal (100) including such composite amplifier and to a method for improving the efficiency of such composite amplifier in particular. The composite amplifier according to embodiments of the present invention is arranged to be connected to an output combiner network (43, 53, 63, 73, 83) and to a load (49, 130). the output combiner network comprising at least one dynamically tuneable reactance (47, 48). The instantaneous efficiency of the composite amplifier (3, 4, 120) is increased by tuning the impedances/admittances seen by each of said at least two power amplifiers (41, 42, 71, 72). The amplifiers being differently driven and they may further be part of a Chireix outphasing system or a pair of a Doherty amplifier.

Abstract: A signal amplification device includes: a signal generator which divides an input signal so as to generate a plurality of division signals having a specified amplitude and different phases; a plurality of amplifiers which amplify the plurality of division signals by using a field effect transistor, respectively; transmission lines through which the division signals pass, the division signals being amplified with individual amplifiers of the plurality of amplifiers, the transmission lines have different lengths and no isolation is provided between ends of the transmission lines; and a detector which performs a comparison between gate currents input to the individual amplifiers to detect whether an input of the division signal to any of the plurality of the amplifiers exceeds a saturation level.

Abstract: An amplifier circuit includes a first amplifier operable to turn on at a first power level, a second amplifier operable to turn on at a second power level below the first power level and a third amplifier operable to turn on at all power levels. A first power combiner is operable to combine an output of the third amplifier with an output of the second amplifier at a first power combining node to form a first combined amplifier output. A second power combiner is operable to combine the first combined amplifier output with an output of the first amplifier at a second power combining node to form a second combined amplifier output. An impedance transformer is operable to transform a load impedance of the amplifier circuit to a transformed impedance at the second power combining node, the transformed impedance matching an impedance of the first and second power combiners.

Abstract: Multiple low noise amplifiers (LNAs) with combined outputs are disclosed. In an exemplary design, an apparatus includes a front-end module and an integrated circuit (IC). The front-end module includes a plurality of LNAs having outputs that are combined. The IC includes receive circuits coupled to the plurality of LNAs via a single interconnection. In an exemplary design, each of the plurality of LNAs may be enabled or disabled via a respective control signal for that LNA. The front-end module may also include receive filters coupled to the plurality of LNAs and a switchplexer coupled to the receive filters. The front-end module may further include at least one power amplifier, and the IC may further include transmit circuits coupled to the at least one power amplifier.

Abstract: An apparatus and method is disclosed to compensate for one or more offsets in a communications signal. A communications receiver may carry out an offset adjustment algorithm to compensate for the one or more offsets. An initial search procedure determines one or more signal metric maps for one or more selected offset adjustment corrections from the one or more offset adjustment corrections. The offset adjustment algorithm determines one or more optimal points for one or more selected offset adjustment correction based upon the one or more signal maps. The adaptive offset algorithm adjusts each of the one or more selected offset adjustment corrections to their respective optimal points and/or each of one or more non-selected offset adjustment corrections to a corresponding one of a plurality of possible offset corrections to provide one or more adjusted offset adjustment corrections. A tracking mode procedure optimizes the one or more adjusted offset adjustment corrections.

Abstract: Designs and techniques associated with power amplifiers for amplifying RF signals to provide variable power amplification and improved linearity in various RF amplification circuits, including power amplifiers operated under the power back-off conditions.

Abstract: A power amplification apparatus includes a first amplifier turned on at a preset low input power; and a second amplifier connected in parallel with the first amplifier and turned off at a low input power due to a relatively low bias current. Output capacitors of the first amplifier and the second amplifier are compensated for by inductors or microstrip lines of dc power supply paths. An output matching circuit of the first amplifier includes a ?/4 transformer. An output matching circuit of the second amplifier has the phase of 0°. Input matching circuits of the first amplifier and the second amplifier include delay compensation circuits. The output matching circuit of the first amplifier, the output matching circuit of the second amplifier, and a final output matching circuit have the same impedance transformation rates.

Abstract: This disclosure is directed to techniques for preventing or reducing perturbations of an output signal of a differential amplifier caused by ionizing radiation incident upon the amplifier. The amplifier may include an amplification module that includes a plurality of amplification units configured to amplify a difference between a first component and a second component of a differential voltage signal to generate a plurality of amplified difference signals each corresponding to the amplified difference. The amplifier may further include a combination module that combines the plurality of amplified difference signals to generate a common output signal corresponding to the amplified difference.

Abstract: A Doherty amplifier (1) is described which comprises an input terminal (102) for receiving an input signal (101) and an output terminal (103) for providing an amplified signal (104) of the input signal (101). The Doherty amplifier (1) comprises a carrier amplifier stage (300) with a first signal input (311) and a second signal input (312) and a peak amplifier stage (400) with a third signal input (411) and a fourth signal input (421). A signal splitter (200) splits and delays the input signal (101) so that the signal at the first signal input (311) and the signal at the second signal input (321) are 180° apart in phase and that the signal at the third signal input (421) and the fourth signal input (431) are also 180° apart in phase.

Abstract: A system and a method are provided. The system may include (A) a measurement circuit arranged to measure at least a current power level of the input signal; (B) multiple non-linear power amplifiers; wherein different non-linear power amplifiers are associated with different power ranges; (C) a control circuit arranged to: (a) select at least one selected non-linear power amplifier to be used to amplify a second signal based on at least: (i) the current power level of an input signal; (ii) an association between the different power ranges and the different non-linear power amplifiers; (iii) an identity of at least one previously selected non-linear power amplifier; and (b) assist in an activation of the at least one selected non-linear power amplifier; and (D) a signal processing module, configured to process the input signal to provide the second signal such as to at least partially compensate for a non-linearity of each of the at least one selected non-linear power amplifier.

Abstract: An amplifier arrangement for amplifying a radio signal comprising at least a first amplifier module and a second amplifier module is presented wherein a splitter stage for dividing an amplifier stage input signal into several signal portions. The signal portions are amplified in the at least two parallel amplifier modules. A combiner stage combines the separate amplifier output signals into a single amplifier arrangement output signal.

Abstract: A circuit for optimizing a power management system. The circuit includes a first amplifier. The first amplifier is responsive to a first reference signal and operable to supply a first load current. The circuit also includes a second amplifier coupled to the first amplifier. The second amplifier is responsive to a second reference signal and operable to supply a second load current. The second load current is lower in magnitude than the first load current, thereby enabling the first amplifier to operate during a first load condition, and the second amplifier to operate during the first load condition and a second load condition. Further, the circuit includes a resistive element coupled to the first amplifier and the second amplifier, to isolate the first amplifier from the second amplifier.

Abstract: An amplifier including a high supply voltage source and a low supply voltage source and two parallel signal paths. Each signal path is connected to the high and the low supply voltage sources and includes a first amplifier and a second amplifier. The two signal paths are connected to each other only at a common input node and a common output node, so that the respective first amplifiers operate independently of each other. The first amplifiers are configured to convert at least a part of an input voltage signal into a signal current. The signal paths are configured so that the signal current in use drives the respective second amplifier to provide an amplified output current to the common output node.

Abstract: The embodiment relates to a Doherty amplifier, wherein in order to perform impedance matching. The embodiment comprises an impedance converter and a connector. The impedance converter includes a plurality of lines having different lengths and disposes between an output end of a carrier amplifier and an output end of a peaking amplifier. The connector connects a line selected from the plurality of lines having different lengths of the impedance converter to the output end of the carrier amplifier and to the output end of the peaking amplifier.

Abstract: In a Doherty amplifier (100), the amplifier's input is connected to a main device (102) via a first branch and to a peak device via a second branch. The first branch has a first frequency-dependent input impedance with a first real part and a first imaginary part. The second branch has a second frequency-dependent input impedance with a second real part and a second imaginary part. The first and second imaginary parts have opposite polarity. The first and 5 second imaginary parts have a same magnitude so as to compensate each other in the frequency band. The first imaginary part and the second imaginary part implement a first phase shift in the. first branch and a second phase shift in the second branch, respectively. The first and second phase shifts each have a magnitude of substantially 45 degrees substantially in the middle of the frequency band and are of opposite polarity.

Abstract: A power amplifier using N-way Doherty structure with adaptive bias supply power tracking for extending the efficiency region over the high peak-to-average power:ratio of the multiplexing modulated signals such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. In an embodiment, present invention uses a dual-feed distributed structure to an N-way Doherty amplifier to improve the isolation between at least one main amplifier and at least one peaking amplifier and, and also to improve both gain and efficiency performance at high output back-off power. Hybrid couplers can be used at either or both of the input and output. In at least some implementations, circuit space is also conserved due to the integration of amplification, power splitting and combining.

Abstract: An amplifier circuit includes a first amplifier operable to turn on at a first power level, a second amplifier operable to turn on at a second power level below the first power level and a third amplifier operable to turn on at all power levels. A first power combiner is operable to combine an output of the third amplifier with an output of the second amplifier at a first power combining node to form a first combined amplifier output. A second power combiner is operable to combine the first combined amplifier output with an output of the first amplifier at a second power combining node to form a second combined amplifier output. An impedance transformer is operable to transform a load impedance of the amplifier circuit to a transformed impedance at the second power combining node, the transformed impedance matching an impedance of the first and second power combiners.

Abstract: A power amplifier comprises a plurality of primary inductors provided on a substrate in a circular geometry as a whole; a plurality of amplifier pairs; a secondary inductor; and a connection wiring. Each amplifier pair is coupled to two ends of a corresponding primary inductor, and amplifies and output to the corresponding primary inductor a pair of first and second signals given as differential input signals, respectively. The secondary inductor is provided adjacent to the primary inductors in a circular geometry, further combines and outputs signals made by combining first and second signals in each primary inductor. The connection wiring is provided inside the primary inductors on the substrate and electrically couples middle points of respective primary inductors with each other.

Abstract: An amplifier circuit can include a first supply terminal to receive a first reference voltage; a second supply terminal to receive a second reference voltage; a first pair of circuit paths extending between the first and second supply terminals and including a respective output terminal, the first pair of circuit paths including a first pair of transistors, each having a gate connected to a respective one of the input terminals and a source connected to the first supply terminal, and a second pair of transistors, each having a gate connected via a first impedance to a gate of a respective first transistor, and a source coupled to the second supply terminal.

Abstract: A distributed low noise amplifier (DLNA) comprises at least a first amplifier part 30.1 providing a first path 36.1 form an input of the amplifier to an output of the amplifier and a second amplifier part 30.2 providing a second path 36.2 from the input to the output. Each of the first and second paths being associated with a respective and different change in phase. The difference being larger than degrees in a noise suppression band to cause a phase difference between noise generated by the amplifier arrangement propagating along the first and second paths and destructive interference of the noise before the output of the DLNA, thereby to suppress noise in the noise suppression band. The respective gains of the amplifier parts 30.1 to 30.n may decrease in a direction from the input of the amplifier to the output thereof.

Abstract: A power amplifier according to the present invention includes: a carrier amplifier (2) that amplifies a carrier of a high-frequency input signal; a peak amplifier (3) that amplifies a peak component of the high-frequency input signal; an average power level detecting circuit (11) that detects an average power level of the high-frequency input signal; a peak power level detecting circuit (12) that detects a peak power level of the high-frequency input signal; a first voltage controller (10a) that controls a DC voltage supplied to the carrier amplifier (2) according to an output voltage signal from the average power level detecting circuit (11); and a second voltage controller (10b) that controls a DC voltage supplied to the peak amplifier (3) according to an output voltage signal from the peak power level detecting circuit (12).

Abstract: A three way wideband Doherty amplifier circuit includes a first peaking amplifier operable to turn on at a first power level, a second peaking amplifier operable to turn on at a second power level below the first power level and a main power amplifier operable to turn on at all power levels. The main power amplifier has a high impedance load modulated state when the first and second peaking amplifiers are turned off. The three way wideband Doherty amplifier circuit further includes a constant impedance combiner connected to an output of each amplifier. The constant impedance combiner has a characteristic impedance which matches the impedance of the main amplifier in the high impedance load modulated state with or without an output matching device connecting the main amplifier output to the constant impedance combiner, as viewed from the output of the main amplifier.

Abstract: A Doherty power amplification apparatus and method using a combined cell are provided. The Doherty power amplification apparatus includes, a power splitter for splitting an input power, and outputting the split powers to a carrier amplification unit and (N?1) peaking amplification units, wherein the carrier amplification unit, including M carrier power amplifiers, for amplifying power output from the power splitter; the (N?1) peaking amplification units, each of which includes M peaking power amplifiers, for amplifying the respective split powers output from the power splitter, and a power combiner for combining a power amplified by the carrier amplification unit and the respective split powers amplified by the (N?1) peaking amplification units, and for outputting the combined power, wherein N represents an integer obtained by adding a number of the carrier amplification units and a number of the (N?1) peaking amplification units, and M represents an integer which is equal to or more than 1.

Abstract: Power amplifier circuits which constitute an RF power module used for a digital device capable of handling high frequency signals in two frequency bands are disposed over the same IC chip. The power amplifier circuits are disposed around the IC chip, and a secondary circuit is disposed between the power amplifier circuits. Thus, the power amplifier circuits are provided within the same IC chip to enable a size reduction. Further, the distance between the power amplifier circuits is ensured even if the power amplifier circuits are provided within the same IC chip. It is therefore possible to suppress the coupling between the power amplifier circuits and restrain crosstalk between the power amplifier circuits.

Abstract: A three way wideband Doherty amplifier circuit includes a first peaking amplifier operable to turn on at a first power level, a second peaking amplifier operable to turn on at a second power level below the first power level and a main power amplifier operable to turn on at all power levels. The main power amplifier has a high impedance load modulated state when the first and second peaking amplifiers are turned off. The three way wideband Doherty amplifier circuit further includes a constant impedance combiner connected to an output of each amplifier. The constant impedance combiner has a characteristic impedance which matches the impedance of the main amplifier in the high impedance load modulated state with or without an output matching device connecting the main amplifier output to the constant impedance combiner, as viewed from the output of the main amplifier.

Abstract: An exemplary apparatus is disclosed that comprises a plurality of voltage to current transducers to convert an input signal voltage into a plurality of input signal currents and a cascode stage. The cascode stage is coupled to the voltage to current transducers to provide amplifier gain control. The cascode stage comprises a thin gate oxide transistor and a thick gate oxide transistor.

Abstract: An amplifier includes first and second amplifier circuits. The first amplifier circuit amplifies positive-phase input signal to obtain a first positive-phase signal and amplifies negative-phase input signal to obtain a first negative-phase signal. The second amplifier circuit includes first and second amplifier units. The first amplifier unit amplifies positive-phase input signal to obtain a second positive-phase signal and amplifies negative-phase input signal to obtain a second negative-phase signal. The second amplifier unit amplifies positive-phase input signal to obtain a third positive-phase signal and amplifies negative-phase input signal to obtain a third negative-phase signal. The positive-phase output signal is sum of first and second positive-phase signals while the negative-phase output signal is sum of first and second negative-phase signals.

Abstract: The invention relates to a final stage three-way power combining amplifying circuit applied to power amplifier of a mobile communications base station system. The circuit includes at least a first power divider, a power combiner, a Doherty amplifier and a Class AB amplifier, as well as some transmission lines and phase-shift lines. A first output port of the first power divider is connected to a first input port of the power combiner via a first phase-shift line and the Doherty amplifier by concatenating them with transmission lines. A second output port of the first power divider is connected to an input terminal of a Class AB amplifier via a transmission line, an output terminal of the Class AB amplifier is connected to a second input port of the power combiner via a microstrip line, and the output terminal of the power combiner outputs an amplified radio frequency signal. The invention can meet the requirements of both high efficiency and low cost.

Abstract: Apparatus and methods for electronic amplification are provided. In one embodiment, a method includes providing a first differential amplification block, providing a second differential amplification block, electrically connecting the first and second differential amplification blocks in a stack between a first voltage reference and a second voltage reference, amplifying a first signal using the first differential amplification block, and amplifying a second signal using the second differential amplification block. A voltage difference between the first and second voltage references defines a power supply voltage, and the first differential amplification block operates over a first range of the power supply voltage and the second differential amplification block operates over a second range of the power supply voltage.

Abstract: There is provided a multi-mode power amplifier operable in a low power mode having a preset power range and in a high power mode having a power range higher than the power range of the low power mode. The multi-mode power amplifier includes: a high power amplifying unit including at least one cascode amplifier to amplify an input signal to a high power level having a preset power range; a low power amplifying unit sharing a common source node of the at least one cascode amplifier to amplify the input signal to a low power level having a power range lower than the high power level; and a coupling unit coupling a transfer path of a signal output from the high power amplifying unit and a transfer path of a signal output from the low power amplifying unit to each other.

Abstract: An active splitter circuit arrangement includes a first amplification module having a number of first input ports and first output ports. The first amplification module is configured to provide first stage amplification to a received input signal and produce from the amplified input signal a number of output signals, each substantially matching the input signal. Also included is a first gain control device having a number of gain input ports respectively coupled to the first output ports and a gain output port coupled to at least one of the first input ports. The first gain control device is configured to control a gain of the first amplification module. Next, a number of second amplification modules corresponding to the number of output signals has a number of second input ports respectively coupled to the first output ports.

Abstract: A radio frequency (RF) power amplifier system having a power detection feature includes a balanced power amplifier, an in-phase branch current detector, an out-of-phase branch current detector, and detection circuitry. The balanced power amplifier includes a phase splitter, an in-phase power amplifier branch, an out-of-phase power amplifier branch, and a phase combiner. The in-phase branch current detector provides an indication of current in the in-phase power amplifier branch. The out-of-phase branch current detector provides an indication of current in the out-of-phase power amplifier branch. The detection circuitry combines the indications of current in the in-phase and out-of-phase power amplifier branches to produce an indication of current in the balanced power amplifier.

Abstract: An amplifier includes a separating unit, a generator, first to fourth switching amplifiers, and an outputting unit. The separating unit separates a pulse signal into a first separated pulse signal and a second separated pulse signal. The generator generates first to fourth low speed pulse signals by using the first and the second separated pulse signal. The first switching amplifier amplifies the first low speed pulse signal. The second switching amplifier amplifies the second low speed pulse signal by using the output of the first switching amplifier as a power-supply. The third switching amplifier amplifies the third low speed pulse signal. The fourth switching amplifier amplifies the fourth low speed pulse signal by using the output of the third switching amplifier as a power-supply. The outputting unit combines and outputs the first and the second output pulse signal.

Abstract: The present invention relates to a Multi-Band Doherty amplifier. Embodiments of the present invention provide an amplifying structure including a main amplifier configured to amplify a first signal, a peak amplifier configured to amplify a second signal, a tunable impedance inverter configured to perform impedance inversion to modulate a load impedance of the main amplifier, and a combining node configured to receive the amplified second signal from the peak amplifier and an output of the tunable impedance inverter. The tunable impedance inverter includes a tuner configured to tune the impedance inversion over at least one broad frequency band. The tuner is (i) at least one capacitor, (i) at least one varactor, or (ii) at least one open stub shunted by a diode.

Abstract: A power amplifier comprises a plurality of primary inductors provided on a substrate in a circular geometry as a whole; a plurality of amplifier pairs; a secondary inductor; and a connection wiring. Each amplifier pair is coupled to two ends of a corresponding primary inductor, and amplifies and output to the corresponding primary inductor a pair of first and second signals given as differential input signals, respectively. The secondary inductor is provided adjacent to the primary inductors in a circular geometry, further combines and outputs signals made by combining first and second signals in each primary inductor. The connection wiring is provided inside the primary inductors on the substrate and electrically couples middle points of respective primary inductors with each other.

Abstract: The RF power amplifier circuit including multiple amplification stages has a previous-stage amplifier, a next-stage amplifier and a controller. The previous-stage amplifier responds to an RF transmission input signal. The next-stage amplifier responds to an amplification signal output by the previous-stage amplifier. In response to an output-power-control voltage, the controller controls the former- and next-stage amplifiers in quiescent current and gain. In response to the output-power-control voltage, the quiescent current and gain of the previous-stage amplifier are continuously changed according to a first continuous function, whereas those of the next-stage amplifier are continuously changed according to a second continuous function. The second continuous function is higher than the first continuous function by at least one in degree. The RF power amplifier circuit brings about the effect that the drop of the power added efficiency in low and middle power modes is relieved.

Abstract: Disclosed is a multi-band power amplifier capable of operating at multiple frequency bands. The multi-band power amplifier includes: a power amplification unit which amplifies an input signal; a matching network circuit which provides impedance matching between the power amplification unit and a load; and an auxiliary amplification unit which additionally supplies a certain magnitude of electric current to the load.

Abstract: System providing switchable impedance transformer matching for power amplifiers. In an exemplary implementation, an amplifier providing switchable impedance matching includes an output inductor (L1) that is part of an output path of the amplifier and a first amplifier stage comprising a first inductor (L4) coupled to the output inductor, the first inductor configured to couple a signal amplified by the first amplifier stage at a first power level to the output inductor in response to a first enable signal. The amplifier also includes a second amplifier stage comprising a second inductor (L5) coupled to the output inductor, the second inductor configured to couple the signal amplified by the second amplifier stage at a second power level to the output inductor in response to a second enable signal.

Abstract: Amplifiers with improved linearity and noise performance are described. In an exemplary design, an apparatus includes first through sixth transistors. The first transistor receives an input signal and provides an amplified signal. The second transistor receives the amplified signal and provides signal drive for an output signal. The third transistor receives the input signal and provides an intermediate signal. The fourth transistor provides bias for the third transistor in a high linearity mode. The fifth transistor receives the intermediate signal and provides signal drive for the output signal in a low linearity mode. The third and fourth transistors form a deboost path that is enabled in the high linearity mode to improve linearity. The third and fifth transistors form a cascode path that is enabled in the low linearity mode to improve gain and noise performance. The sixth transistor generates distortion component used to cancel distortion component from the first transistor.

Abstract: One exemplary signal amplification circuit used for processing an input signal includes an input stage, a plurality of output stages, and a selecting stage. The input stage has an input node for receiving the input signal and an output node for outputting an intermediate signal. The output stages are coupled to a plurality of output ports of the signal amplification circuit, respectively. Each of the output stages generates a corresponding processed signal to a corresponding output port according to a gain and a signal derived from the intermediate signal of the input stage when enabled. The selecting stage is arranged for selectively coupling the output node of the input stage to at least one of the output stages.

Abstract: Provided is a distributed Doherty power amplifier exhibiting high efficiency and linearity at a wide range of bandwidths, the distributed Doherty power amplifier including a first amplifier; a second amplifier, which is connected to the first amplifier in parallel; a first shifting unit, which is interconnected between the input of the first amplifier and the input of the second amplifier and inverses the phase of the input of the second amplifier; and a second shifting unit, which is interconnected between the output of the first amplifier and the output of the second amplifier and inverses the phase of the output of the second amplifier, wherein the first amplifier and the second amplifier are Doherty power amplifiers, and each of the Doherty power amplifiers includes a carrier amplifier and a peaking amplifier, which are connected in parallel.