Qualcomm Incorporated

Telefonaktiebolaget Lm Ericsson (publ)

Thomas Domenick Marra

Gurkanwal Singh Sahota

Nathan M Pletcher

Aristotele Hadjichristos

Lennart Karl Mathe

Song Shi

Joseph Duncan

Chi Fan Yung

Zhiqing Zhang

Jun Hua

Tamer Adel Kadous

Hemanth Sampath

Inyup Kang

Roberto Rimini

Bhushan Shanti Asuri

Vladimir Aparin

Todd Robert Sutton

Arash Mirbagheri

Shrenik Patel

Steven C Ciccarelli

Jeremy H Lin

Christian Holenstein

Prashanth Akula

Junxiong Deng

Paul J Draxler

Iulian Mirea

Soon-Seng Lau

Philip David Coan

Mohammad Farazian

Heng-Yu Jian

Certain aspects of the present disclosure provide methods and apparatus for generating an envelope tracking power supply voltage. For example, certain aspects of the present disclosure provide an envelope tracking power supply having a linear amplifier having an output coupled to a power supply node of an amplifier, wherein a power supply node of the linear amplifier is coupled to a first voltage supply node. The envelope tracking power supply may also include a switch mode power supply having an output coupled to the power supply node of the amplifier. Certain aspects also include a circuit having a first switch coupled to the first voltage supply node and a second switch coupled to a second voltage supply node, wherein a power supply node of the switch mode power supply is coupled to the first switch and the second switch.

Selecting between boosted supply and battery supply

Certain aspects of the present disclosure provide methods and apparatus for operating an envelope tracking power supply. The method may include receiving, from a modem of a device, information indicative of a transmit waveform statistic of a signal to be wirelessly transmitted by the device. The method may further include adjusting a configuration of the envelope tracking power supply based on the transmit waveform statistic of the signal.

Adjusting envelope tracking power supply

Exemplary embodiments are related to digital pre-distortion in envelope tracking systems. A device may include an amplitude modulation-to-phase modulation (AM-PM) distortion unit configured to generate an AM-PM distortion component in response to receipt of phase data of an input transmit signal. The device may also include a local oscillator (LO) path coupled to the distortion unit and configured to convey a local oscillator (LO) signal that varies based on the AM-PM distortion component.

Pre-distortion in a wireless transmitter

Techniques for monitoring and controlling bias current of amplifiers are described. In an exemplary design, an apparatus may include an amplifier and a bias circuit. The amplifier may include at least one transistor coupled to an inductor. The bias circuit may generate at least one bias voltage for the at least one transistor in the amplifier to obtain a target bias current for the amplifier. The bias circuit may generate the at least one bias voltage based on a voltage across the inductor in the amplifier, or a current through a current mirror formed with one of the at least one transistor in the amplifier, or a gate-to-source voltage of one of the at least one transistor in the amplifier, or a voltage in a replica circuit replicating the amplifier, or a current applied to the amplifier with a switched mode power supply disabled.

Bias current monitor and control mechanism for amplifiers

A modem is described. The modem includes a transmitter. The transmitter includes a digital pre-distortion module and a power amplifier. The modem also includes one or more selected shared receivers. The one or more selected shared receivers generate a feedback signal for the digital pre-distortion module. The modem further includes a feedback switch. The feedback switch selectively couples the one or more selected shared receivers to an output of the transmitter.

Shared feedback for adaptive transmitter pre-distortion

A method for interference reduction is described. The method is implemented in a wireless device. It is determined that a page is going to be received via a secondary receiver. It is also determined that a digital-to-analog converter (DAC) image from a transmitter will cause interference with the secondary receiver when the page is received. A sampling frequency of the DAC for the transmitter is changed so that there are not any DAC images from the transmitter that will cause interference with the secondary receiver.

Dynamically changing a transmitter sampling frequency for a digital-to-analog converter (DAC) to reduce interference from DAC images

Techniques for efficiently generating a power supply are described. In one design, an apparatus includes an envelope amplifier and a boost converter. The boost converter generates a boosted supply voltage having a higher voltage than a first supply voltage (e.g., a battery voltage). The envelope amplifier generates a second supply voltage based on an envelope signal and the boosted supply voltage (and also possibly the first supply voltage). A power amplifier operates based on the second supply voltage. In another design, an apparatus includes a switcher, an envelope amplifier, and a power amplifier. The switcher receives a first supply voltage and provides a first supply current. The envelope amplifier provides a second supply current based on an envelope signal. The power amplifier receives a total supply current including the first and second supply currents. In one design, the switcher detects the second supply current and adds an offset to generate a larger first supply current than without the offset.

Low-voltage power-efficient envelope tracker

An exemplary embodiment discloses a digital control block for dynamically regulating power consumption of the transmitter; and a first driver amplifier circuit comprising a plurality of bias-modes each corresponding to a power consumption level in the transmitter, the digital control block to instruct the first driver amplifier circuit to operate in a selected bias-mode to regulate power consumption of the transmitter.

Reduced power-consumption transmitters

A method for interference reduction is described. A sampling frequency is selected for a digital-to-analog converter (DAC) so that images within a DAC output signal do not interfere with one or more receivers. A sample rate is adjusted of an input signal that is provided to the DAC to match the sampling frequency for the DAC.

Interference reduction using variable digital-to-analog converter (DAC) sampling rates

Bandwidth reduction of amplitude and/or phase components of relatively wide bandwidth composite signal. In an exemplary embodiment, an EER amplifier system for CDMA signal amplification includes an amplitude bandwidth reduction module included in an amplitude signal component path and a phase bandwidth reduction module is included in a phase signal component path, for controlling an RF amplifier. The phase bandwidth reduction module may reduce the phase component bandwidth of the input signal by, for example, generating a non-linear relationship between phase signal amplitude and input signal amplitude. The amplitude bandwidth reduction module may reduce the amplitude component bandwidth of the input signal by, for example, generating a non-linear relationship between the supply voltage to the RF amplifier and an input signal amplitude.

Systems and methods for amplification of a communication signal

A biasing circuit for biasing a device (e.g., a GaAs field effect transistor) used for amplifying a radio frequency (RF) signal, the biasing circuit including an active element in series with a resistor, the active element providing a relatively low impedance over a bandwidth comparable to an amplitude modulation bandwidth of the RF signal, such that a DC bias voltage applied at the active element has a fixed DC voltage at the resistor input, i.e., without any memory effect, thereby allowing for improved predistortion compensation of non-linear voltage of the RF signal.

Active element bias circuit for RF power transistor input

Second-order harmonic tuning of an active device, such as a transistor used in a radio frequency (RF) power amplifier circuit, is accomplished by positioning a quarter-wavelength stub along a transmission line coupled to an output of the device, such that the output is presented with a desired impedance for the second harmonic.

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Del Mar, CA, United States of America

Thomas Domenick Marra