A multiphase power supply includes a multiphase converter including first and second converters having differing operating phases, each of the first and second converters configured to convert input power into driving power, and transmit the driving power to a power amplifier, a detector configured to detect a voltage based on the driving power, and a duty controller configured to compare an error voltage between an envelope signal of an input signal input into the power amplifier and the detected voltage and sawtooth wave signals having different phases from each other to generate duty control signals, wherein the duty controller compares the error voltage and the sawtooth wave signals with each other using a single comparator.

A method of characterizing an envelope tracking amplification stage, the method comprising: generating an input test waveform which is representative of an input waveform under normal operating conditions of the amplification stage; applying a respective one of a plurality of different shaping functions, each comprising a non-linear transfer function, to the input signal envelope in each of a plurality of test periods during the period in which the input test waveform is applied as the input signal to generate the input to the envelope tracking modulated supply voltage; measuring parameters of the amplification stage during the period in which the input test waveform is applied in order to allow determination of the gain, phase and efficiency characteristics of the amplifier; and for each of the gain, phase and efficiency characteristics, generating a three dimensional plot of the characteristic with respect to input power and supply voltage applied to the amplifier.

Techniques for efficiently generating a variable boosted supply voltage for an amplifier and/or other circuits are disclosed. In an exemplary design, an apparatus includes an amplifier, a boost converter, and a boost controller. The amplifier receives an envelope signal and a variable boosted supply voltage and provides an output voltage and an output current. The boost converter receives a power supply voltage and at least one signal determined based on the envelope signal and generates the variable boosted supply voltage based on the power supply voltage and the at least one signal. The boost controller generates the at least one signal (e.g., an enable signal and/or a threshold voltage) for the boost converter based on the envelope signal and/or the output voltage. The boost converter is enabled or disabled based on the enable signal and generates the variable boosted supply voltage based on the power supply voltage and the threshold voltage.

Example power amplifier chips and communication devices are described. One example power amplifier chip includes a package housing and a plurality of power amplifier dies. The plurality of power amplifier dies are packaged in the package housing, and each of the plurality of power amplifier dies includes at least one stage of power amplifier.

The behavioral model and predistorter for modeling and reducing nonlinear effects in power amplifiers addresses the model size estimation problem. The GMP model is replaced by the hybrid memory polynomial/envelope memory polynomial (HMEM) model within a twin nonlinear two-box structure to reduce the number of variables involved in the model size estimation problem, without compromising model accuracy and digital predistorter performance. A sequential approach is presented to efficiently estimate the model size. Experimental validation is carried out to evaluate the performance of the size estimation and the accuracy of the HMEM-based twin-nonlinear two-box model with respect to that of the GMP-based twin-nonlinear two-box model.

To provide a monitoring system capable of monitoring, without stopping operations for a long period of time, a change of the characteristics of an apparatus to be subjected to characteristic measurement, to which high frequency signals are inputted. [Solution] A signal to be monitored and a reference signal are inputted to an input unit 11 , and the input unit inputs one of the inputted signals to an apparatus 15 to be subjected to characteristic measurement. On the basis of an output signal of the apparatus 15 and the reference signal in the cases where the reference signal is inputted to the apparatus, an input/output characteristic calculation unit 12 calculates the input/output characteristics of the apparatus 15 . On the basis of calculation results obtained from the input/output characteristic calculation unit 12, a correction result generating unit 13 generates a correction result signal that indicates the results obtained by correcting an output signal of the apparatus 15 in the cases where the signal to be monitored is inputted to the apparatus. On the basis of the correction result signal generated by the correction result generating unit 13 , a failure determining unit 14 determines whether the apparatus has a failure.

A transmitter is provided. The transmitter includes a bus system including at least two bus lines. Further, the transmitter includes an envelope tracking circuit coupled to the at least two bus lines, and a plurality of power amplifiers. At least a first one of the plurality of power amplifiers, while in active state, is configured to selectively couple its input to the one of the at least two bus lines which is supplied with a supply voltage or a bias signal by the envelope tracking circuit that is based on an envelope of a first baseband signal related to a first radio frequency signal received by the first one of the plurality of power amplifiers for amplification.

Envelope tracking systems with modeling for power amplifier supply voltage filtering are provided herein. In certain embodiments, an envelope tracking system includes a supply voltage filter, a power amplifier that receives a power amplifier supply voltage through the supply voltage filter, and an envelope tracker that generates the power amplifier supply voltage. The power amplifier provides amplification to a radio frequency (RF) signal that is generated based on digital signal data, and the envelope tracker generates the power amplifier supply voltage based on an envelope signal corresponding to an envelope of the RF signal. The envelope tracking system further includes digital modeling circuitry that models the supply voltage filter and operates to digitally compensate the digital signal data for effects of the supply voltage filter, such as distortion.

An envelope tracking (ET) power management apparatus incorporating multiple power amplifiers is provided. The ET power management apparatus includes a single ET integrated circuit (ETIC) configured to provide multiple ET voltages to the multiple power amplifiers for amplifying a radio frequency (RF) signal concurrently. The ETIC includes multiple first ET voltage circuits configured to generate multiple first ET voltages and a second ET voltage circuit configured to generate a second ET voltage. The ETIC is configured to provide each of the first ET voltages to an output stage amplifier(s) in a respective one of the power amplifiers and provide the second ET voltage to a driver stage amplifier in all of the power amplifiers. By supporting the multiple power amplifiers using a single ETIC, it is possible to reduce footprint, power consumption, and heat dissipation in an electronic device employing the ET power management apparatus.

Power amplifiers with adaptive bias for envelope tracking applications are provided herein. In certain embodiments, an envelope tracking system includes a power amplifier that amplifies a radio frequency (RF) signal and that receives power from a power amplifier supply voltage, and an envelope tracker that controls a voltage level of the power amplifier supply voltage based on an envelope of the RF signal. The power amplifier includes a current mirror having an input that receives a reference current, an output electrically connected to the power amplifier supply voltage, and a node that outputs a gate bias voltage. The power amplifier further includes a field-effect transistor that amplifies the radio frequency signal and a first depletion-mode transistor having a gate connected to the node of the current mirror and a source connected to a gate of the field-effect transistor.