Skyworks Solutions, Inc.

Snaptrack Incorporated

Conexant Systems, Inc.

Nujira Limited

Sabah Khesbak

Florinel G Balteanu

Hardik Bhupendra Modi

David Steven Ripley

Serge Francois Drogi

Roman Zbigniew Arkiszewski

Yevgeniy A Tkachenko

Robert John Thompson

Jeffrey Gordon Strahler

Guohao Zhang

David Richard Pehlke

Robert Astle Henshaw

Julian Hildersley

Kevin Lee Cobley

Benjamin Bartram

Shayan Farahvash

Cyrille Rio

Madhukar Reddy

Trevor Robinson

Mark Alan Richey

San Chin

Pramote Piriyapoksombut

Ari T Vauhkonen

Kimmo J Salmela

Apparatus and methods for adaptive power amplifier biasing are provided. In certain embodiments, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, and a power amplifier bias control circuit that generates a bias signal of the power amplifier based on a bandwidth signal indicating a bandwidth of the RF signal. The power amplifier bias control circuit has a bandwidth that adapts to the bandwidth of the RF signal as indicated by the bandwidth signal.

Apparatus and methods for adaptive power amplifier biasing

Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker is provided for a power amplifier that amplifies a radio frequency (RF) signal. The envelope tracker controls a power amplifier supply voltage of the power amplifier based on an envelope signal indicating an envelope of the RF signal. The envelope tracker includes a first controllable resistance between a first regulated voltage and the power amplifier supply voltage and a second controllable resistance between a second regulated voltage and the power amplifier supply voltage. The first regulated voltage and the second regulated voltage are of different voltage levels.

Apparatus and methods for envelope tracking

Distributed radio frequency (RF) communication systems for automotive are disclosed herein. In certain embodiments, an RF communication system for an automobile includes an RF module located close to an antenna to satisfy a specified output power with small insertion loss. Additionally, the baseband processor is placed remotely from the RF module in a different area of the automobile to provide a lower temperature environment. Additionally, the RF module communicates with the baseband processor in a digital format eliminating the need for higher cost cabling (for instance, due to higher noise immunity arising from using digital signaling) and using digital transfer cabling, which can already be present in the automobile for other purposes. The RF module can include an RF front-end (RFFE) and a transceiver used for providing frequency conversion, for instance, between RF and baseband.

Distributed radio frequency communication systems for automotive

Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker is provided for a power amplifier that amplifies an RF signal. The envelope tracker includes a multi-level switching circuit having an output that provides an output current that changes in relation to an envelope signal indicating an envelope of the RF signal when the envelope tracker is operating in an envelope tracking mode. The multi-level switching circuit includes a multi-level supply (MLS) modulator that receives multiple regulated voltages of different voltage levels, and an MLS control circuit that controls the selection of the MLS modulator over time based on the envelope signal. When transitioning the MLS modulator from selection of one regulated voltage level to another regulated voltage level, the MLS control circuit provides a soft transition to gradually switch the regulated voltage levels.

Apparatus and methods for envelope tracking systems with automatic mode selection are provided herein. In certain configurations, a power amplifier system includes a power amplifier configured to provide amplification to a radio frequency signal and to receive power from a power amplifier supply voltage, and an envelope tracker including a signal bandwidth detection circuit configured to generate a detected bandwidth signal based on processing an envelope signal corresponding to an envelope of the radio frequency signal. The envelope tracker further includes a switch bank configured to receive a plurality of regulated voltages, a filter configured to filter an output of the switch bank to generate the power amplifier supply voltage, and a mode control circuit configured to control a filtering characteristic of the filter based on the detected bandwidth signal.

Apparatus and methods for envelope tracking systems with automatic mode selection

Fast envelope tracking systems are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator and a differential error amplifier configured to operate in combination with one another to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The envelope tracking system further includes a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to the envelope of the RF signal. Additionally, the differential error amplifier generates an output current operable to adjust a voltage level of the power amplifier supply voltage based on comparing the single-ended envelope signal to a reference signal.

Fast envelope tracking systems for power amplifiers

Described herein are systems, architectures, circuits, devices, and methods for a DC-DC converter that dynamically adjusts a supply voltage to a power amplifier based on the number of resource blocks in a signal to be transmitted. The disclosed technologies estimate the number of resource blocks in a signal, generate a signal corresponding to the estimated number of resource blocks, and modify a supply voltage based on the generated signal. These technologies can be used to increase the efficiency of power amplifier systems for cellular signals being transmitted that have fewer resource blocks than is typically assumed (e.g., at least 100 resource blocks).

Method of modifying a supply voltage to a power amplifier based on estimated number of resource blocks

High bandwidth envelope trackers are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator that operates in combination with a high bandwidth amplifier to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The high bandwidth amplifier includes an output that generates an output current for adjusting the power amplifier supply voltage, a first input that receives a reference signal, and a second input that receives an envelope signal indicating the envelope of the RF signal. The second input has lower input impedance than the first input to provide a rapid transient response and high envelope tracking bandwidth.

Wide bandwidth envelope trackers

Envelope trackers providing compensation for power amplifier output load variation are provided herein. In certain configurations, a radio frequency (RF) system includes an antenna, a power amplifier that receives a radio frequency signal and outputs an amplified radio frequency signal to the antenna, a plurality of detectors coupled to the power amplifier and operable to generate a plurality of detection signals, and an envelope tracker that controls a supply voltage of the power amplifier based on an envelope of the radio frequency signal. The envelope tracker processes the plurality of detection signals to generate a load variation detection signal indicating a change in an output load of the power amplifier arising from a change in a voltage standing wave ratio (VSWR) of the antenna. Additionally, the envelope tracker adjusts a gain of the power amplifier based on the load variation detection signal.

Envelope trackers providing compensation for power amplifier output load variation

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Irvine, CA, United States of America

Sabah Khesbak