Abstract: Circuits that operate with power supplies of less than 1 Volt are presented. More particularly, circuits that operate with supply voltages near or lower than the threshold voltage of the transistors in those circuits are presented. Various circuits and embodiments such as operational transconductance amplifiers, biasing circuits, integrators, continuous-time sigma delta modulators, track-and-bold circuits, and others are presented. The techniques and circuits can be used in a wide range of applications and various transistors from metal-oxide-semiconductor to bipolar junction transistors may implement the techniques presented herein.

Abstract: Provided is a predistortion apparatus which performs predistortion by reflecting a memory effect when linearizing an output of a nonlinear device using a wideband signal. The predistortion apparatus includes a predistortion unit and a coefficient extraction unit. The predistortion unit selects and outputs one of outputs of the sub-predistorters as an output signal according to intensity of an input signal. The coefficient extraction unit selects one of a plurality of coefficient extractors according to intensity of a nonlinear signal which is generated in response to the output signal, extracts a plurality of predistortion coefficients with the nonlinear signal and the output signal, and delivers the extracted predistortion coefficients to the predistortion unit. Accordingly, the memory effect is reflected even when the input signal is a wideband signal.

Abstract: A circuit for amplifying an input signal can comprise a plurality of couplers. A splitting coupler of the plurality of couplers can receive the input signal and a combining coupler of the plurality of couplers can provides an output signal. N number of amplifiers can be included in the circuit to amplify the input signal, wherein N is a non-binary integer greater than one. At least one of the plurality of couplers can comprise a hybrid coupler that has two ports terminated into substantially equal reactances.

Abstract: An amplifying apparatus includes: a plurality of amplifiers; a linear combiner receiving a plurality of leakage signals resulting from cross leakage between outputs of the plurality of amplifiers and performing a linear combination of level values of the plurality of leakage signals to generate a plurality of linear combination signals; and an output calculator calculating real level values of a plurality of output amplified signals of the amplifiers from level values of the linear combination signals.

Abstract: A supply voltage controller 11 includes a simplified envelope creating unit 111 that calculates an envelope of an input audio signal according to an input audio signal from an external device, creates a supply voltage control signal so that a waveform of the supply voltage control signal follows a waveform of the envelope, and outputs the supply voltage control signal to a voltage variable power supply 12 a constant time before the input audio signal is amplified by the amplifier 14. Accordingly, an amplifying device can be provided which can reduce the distortion of the output signal not depending on a change in the slew rate of the voltage variable power supply 12 and suppress the deterioration of power efficiency.

Abstract: A power amplifying apparatus has a GaN device for RF amplification, a GaN device for monitoring, an Idq detecting circuit, and a gate bias control (GBC) circuit. The GaN device for RF amplification amplifies an input signal to output the resultant. The GaN device for monitoring is an amplification device for monitoring an input/output signal of the GaN device for RF amplification. The Idq detecting circuit detects an output signal output by the GaN device for monitoring, corresponding to an input signal, which is diverged from the input signal to be input to the GaN device for RF amplification, and is input to the GaN device for monitoring. The gate bias control circuit controls a gate voltage to be applied to the GaN device for RF amplification in accordance with the output signal detected by the Idq detecting circuit.

Abstract: A power amplifier circuit, comprising: an input for receiving an input signal to be amplified; a power supply; an amplifier, coupled to the input and the power supply; and a cascode device coupled between the power supply and the amplifier. The circuit is characterized by: a first current source coupled between the input and the amplifier, configured to provide a biasing current which is proportional to absolute temperature; and a second current source for controlling the cascode device, configured to provide a current which is complementary to absolute temperature (CTAT).

Abstract: An integrated circuit for providing a differential interface for an envelope tracking signal is described. The integrated circuit includes a subtraction module having a first input for receiving a digital envelope tracking signal and a second input for receiving a second signal, wherein the subtraction module is arranged to subtract the second signal from the digital envelope tracking signal and produce an envelope tracking signal with a reduced average direct current (DC) component; a digital-to-analog converter (DAC) arranged to receive the envelope tracking signal with the reduced average DC component and produce a differential analog version thereof; and a modulator operably coupled to a differential output of the DAC, wherein the modulator comprises a DC input point arranged to insert a DC component into the differential analog version of the envelope tracking signal.

Abstract: An amplifier with integrated filter (e.g., an LNA) is described. In one design, the amplifier may include a gain stage, a filter stage, and a buffer stage. The gain stage may provide signal amplification for an input signal. The filter stage may provide filtering for the input signal. The buffer stage may buffer a filtered signal from the filter stage. The amplifier may further include a second filter stage and a second buffer stage. The second filter stage may provide additional filtering for the input signal. The second buffer stage may buffer a second filtered signal from the second filter stage. All of the stages may be stacked and coupled between a supply voltage and circuit ground. The filter stage(s) may implement an elliptical lowpass filter. Each filter stage may include an inductor and a capacitor coupled in parallel and forming a resonator tank to attenuate interfering signals.

Abstract: Embodiments of the present invention a power supply circuit of a power amplifier and a terminal, relating to the communication field. The power supply circuit of the power amplifier includes a direct current/direct current converter chip, where the direct current/direct current converter chip includes an input pin, an inductance pin, and a feedback pin, and the input pin is connected to a power supply and the inductance pin is connected to a voltage input end of the power amplifier through an LC storage circuit. A control circuit is connected between the voltage input end of the power amplifier and the feedback pin; the control circuit includes a control voltage, where the control voltage adjusts the voltage at the voltage input end of the power amplifier through the control circuit and the control voltage is variable.

Abstract: A method for processing signals may include, in a conditionally-stable operational amplifier, shifting the gain curve of the conditionally-stable operational amplifier to a desired position, by buffering at least one output signal from at least one transconductance module within the conditionally-stable operational amplifier using a buffer. The desired position of the gain curve may be associated with a desired feedback factor. The shifting of the gain may take place without shifting a corresponding phase. The tuning of the buffer may be based on the desired position of the gain curve which is derived from feedback factor value(s) specified by an application. A phase corresponding to the desired position of the gain curve at 0 dB frequency may be greater than a threshold phase. The buffering may be tuned using at least one tunable wideband buffer so that the corresponding phase at 0 dB frequency remains higher than the threshold phase.

Abstract: A power-amplifier arrangement (35) is disclosed. The power-amplifier arrangement (35) comprises a pulse modulator (40) adapted to receive a digital input signal of the power-amplifier arrangement (35) and generate, based on the digital input signal of the power-amplifier arrangement (35), an output signal of the pulse modulator (40) with a plurality of quantization levels. The pulse modulator has a plurality of output ports (50—1-50_n) for representing the output signal of the pulse modulator (40). Each output port (50—1-50_n) of the pulse modulator (40) is associated with a unique one of the quantization levels such that a signal output on the output port (50—1-50_n) adopts a first state when the output signal of the pulse modulator (40) equals or exceeds the associated quantization level, or, otherwise, a second state. A related radio-transmitter circuit and a related radio-communication apparatus are also disclosed.

Abstract: An electronic circuit is disclosed for driving a switching amplifier. The electronic circuit is configured for generating, when operating in a switch-on mode, a driving signal for driving the switching amplifier. The driving signal carries a plurality of pulses having: an pulse width increasing between contiguous pulses of the plurality of pulses according to a step value having modulus equal to two and odd values; a polarity alternating between the contiguous pulses.

Abstract: A high-frequency signal amplifier includes an amplifier having an input terminal and an output terminal, and amplifying a high-frequency signal; a signal line connected between the output terminal of the amplifier and an antenna; coupled lines arranged in parallel and coupled to the signal line and having different line lengths or differently terminated ends; and phase shifters shifting phase of high-frequency signals applied via the signal line and the coupled lines, supplying the high-frequency signals to the input terminal of the amplifier, and having different amounts of phase change.

Abstract: A system and method of calibrating an amplifier are presented. The amplifier has a first amplification path and a second amplification path. An attenuation of the first amplification path is set to a first attenuation value and an attenuation of the second amplification path is set to the first attenuation value. A first phase shift of the first amplification path and a second phase shift of the second amplification path that meets a first performance criteria is determined. A phase shift of the first amplification path is set to the first phase shift and a phase shift of the second amplification path is set to the second phase shift. A first attenuation of the first amplification path and a second attenuation of the second amplification path that meets a second performance criteria is determined.

Abstract: A Doherty amplifier having a main amplifier branch and one or more peak amplifier branches, where the functionality and structure of the cascade of the main output matching network, the main offset line, and the quarter-wave transformer of the main amplifier branch of a conventional Doherty amplifier are subsumed into the main output matching network of the main amplifier branch, and the functionality and structure of each cascade of the peak output matching network and the peak offset line of each peak amplifier branch of a conventional Doherty amplifier are subsumed into the peak output matching network of the corresponding peak amplifier branch. Furthermore, the output quarter-wave transformer can be replaced by a wideband node matching network that does not have to perform frequency inversion.

Abstract: Embodiments of power amplification devices are described that include a power amplification circuit, a first voltage regulation circuit, and a second voltage regulation circuit. The voltage regulation circuits are configured to provide regulated voltages to the power amplification circuit. The power amplification device also includes a threshold detection circuit to get better maximum output power performance while preserving power efficiency. The threshold detection circuit is configured to increase a voltage adjustment gain of the first voltage regulation circuit when a regulated voltage level of regulated voltage from the second voltage regulation circuit reaches a threshold voltage level. In this manner, the voltage adjustment gain can be increased when the second voltage regulation circuit is close to or has railed.

Abstract: The present application discloses various implementations of a mobile device including a power amplifier (PA) having a driving stage coupled to an output stage. The driving stage is configured to be selectably powered by one of a first voltage supply and a second voltage supply. The output stage is configured to be powered by the second voltage supply. The mobile device further includes a voltage supply selection switch configured to selectably power the driving stage by the second voltage supply when an output power of the PA is less than or equal to a threshold power.

Abstract: A digital pre-distortion (DPD) power amplifying apparatus and a method for digitally controlling synchronization of the DPD power amplifying apparatus, which includes a power amplifier, a bias shifter and a DPD unit, are provided. The method includes acquiring a DPD path delay time at a path along which an input signal is fed back to the DPD unit; delaying an input signal incoming to the power amplifier by the DPD path delay time and acquiring synchronization by delaying a bias signal a predetermined number of times until the bias signal and the delayed input signal are synchronized with each other; and in response to synchronization between the bias signal and the delayed input signal being established, pre-distorting the input signal according to a feedback signal output from the power amplifier.

Abstract: An apparatus and a method for expanding an operation region in an envelope tracking power amplifier are provided. The apparatus for amplifying power of a transmission signal includes an amplitude component determination unit, a supply modulator, and a power amplify module. The amplitude component determination unit determines an amplitude component of a transmission signal. The supply modulator generates a supply voltage to be provided to the power amplify module depending on the amplitude component of the transmission signal determined by the amplitude component determination unit. The power amplify module amplifies power of the transmission signal depending on the supply voltage generated by the supply modulator.