Freescale Semiconductor,inc.

Analog Devices Global

Analog Devices International Unlimited Company

Motorola Corporation

Mediatek Singapore Pte. Ltd.

Analog Devices Global Unlimited Company

Other

Analog Devices,inc.

Patrick Joseph Pratt

Conor O'Keeffe

Michael William O'Brien

David Jennings

Peadar Antony Forbes

Dale Gerard Schwent

Daniel B Schwartz

Thomas D Nagode

Norman Beamish

Mark Cope

Martin McCormick

Ahmed Khalil

Michael Milyard

Denis Dineen

Nadim Khlat

Dong Chen

Christopher Mayer

William Plumb

Charles LeRoy Sobchak

George Norris

Pei-Shiun Chung

Praveen Chandrasekaran

Stephen Summerfield

David Redmond

Joseph Bradford Brannon

Conor O'Keefe

Sophie Gault

Philip C Warder

Ronald Dale Turner

Eoin Edward English

Bernard Mark Tenbroek

Bing Xu

Benjamin Vigoda

John Anthony Cleary

Rares Andrei Bodnar

David J McLaurin

Peter James Tonge

David J Mclaurin

Jacques Trichet

Donal Bourke

Christian Steffen Birk

Rafael Celedon

Hari Thirumoorthy

Louis M Nigra

Dzianis Lukashevich

Elizabeth A Lillis

Jau Horng Chen

Keith A Tilley

Theophane Weber

Aidan Murphy

Wayne Edwards

Jan Crols

John Oates

Claire Masterson

Justine Mary McCormack

David Sayago Montilla

Naveen Naraharisetti

Padraig O'Connor

Kathleen Embrechts

Hossein Yektaii

Wim Rens

Michael O'brien

Hugh O Brien

Ahmed Hassan Abdelaziz Abdelrahman

Robert O'Sullivan

Daniel B Schartz

Bijan Knight Tehrani

Martin Steven McCORMICK

Chris Mayer

Joshua Park

Justine Mary Mccormack

Ronald D Turner

Michael A Milyard

Systems and methods for compensating a transmit signal for charge trapping effects of a power amplifier are provided. In certain embodiments, a non-linear filter is trained based on time aligning a first set of observations taken from digital transmit data prior to conversion to a radio frequency transmit signal, and a second set of observations taken from an output of a power amplifier that amplifies the radio frequency transmit signal. In certain implementations, the first set of observations and the second set of observations are obtained without decimation. Rather, decimation is provided after timing alignment. By implementing the DPD system in this manner, signal data is not lost by decimation and more accurate timing alignment between the sets of observations is achieved.

Systems and methods of compensating a transmit signal for charge trapping effects of a power amplifier

Apparatus and methods provide predistortion for a phased array. Radio frequency (RF) sample signals from phased array elements are provided along return paths and are combined by a hardware RF combiner. Phase shifters are adjusted such that the RF sample signals are phase-aligned when combined. Adaptive adjustment of predistortion for the amplifiers of the phased array can be based on a signal derived from the combined RF sample signals.

Phased array amplifier linearization

Some embodiments herein describe a radio frequency power semiconductor device that include a first non-linear filter network for compensating for lower frequency noise of a power amplifier. The first non-linear filter network can include a plurality of infinite impulse response filters and corresponding corrective elements to correct for a non-linear portion of the power amplifier. The radio frequency power semiconductor device can further include a second non-linear filter network for compensating for broadband distortion. The second non-linear filter network can be connected in parallel to the first non-linear filter network. The broadband distortion can include digital predistortion and the narrowband distortion can include charge trapping effects. The first non-linear filter network can comprise Laguerre filters. The second non-linear filter network can comprise general memory polynomial filters.

Systems and methods of compensating for narrowband distortion in power semiconductor devices

Various examples are directed to systems and methods for operating a plurality of power amplifiers. A predistortion circuit may pre-distort an input signal according to a predistortion configuration to generate a pre-distorted signal for the plurality of power amplifiers. An adaption circuit may receive a first feedback signal from a first power amplifier of the plurality of power amplifiers and generate predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers. The adaption circuit may receive a first feedback signal from a second power amplifier of the plurality of power amplifiers and update the predistortion correlation data to generate updated predistortion correlation data using the first feedback signal from the second power amplifier. The adaption circuit may also generate the predistortion configuration using the updated predistortion correlation data.

Multi-component digital predistortion

The disclosed technology relates generally to semiconductor devices, and more particularly to power semiconductor devices in which effects of charge trapping are compensated. A radio frequency (RF) power transmitter system comprises a RF power semiconductor device that outputs a time-varying gain characteristic from a RF signal input waveform originating from a digital input, wherein the time-varying gain characteristic includes a gain error associated with charge-trapping events having a memory effect on the RF power semiconductor device lasting longer than 1 microsecond. The RF power transmitter system further comprises circuitry configured to apply an analog gate bias waveform to the RF power semiconductor device based on the time-varying gain characteristic to reduce the gain error.

Power semiconductor device with charge trapping compensation

An apparatus that implements DPD in a manner that can address OOB instability issues, PE instability issues, or both, is disclosed. The apparatus includes an actuator circuit configured to use a model of a power amplifier (PA) to apply a predistortion to at least a portion of an input signal, and an error correction circuit configured to generate an error signal indicative of a deviation of the output of the actuator circuit from the target output, e.g., in terms of OOB or PE. The apparatus also includes an adaptation circuit configured to update the model based on the error signal. By using such an error in adapting the model used for the DPD, undesirable effects of performing DPD, such as creation or amplification of OOB frequency components, or increasing amplitude of some samples, may be reduced or eliminated.

Digital predistortion with out-of-band and peak expansion regularization

An example apparatus includes a power amplifier (PA) and a linearity optimizer. The optimizer includes a PA actuator and a linearity adaptation circuit. The actuator is configured to generate an actuator output based on an actuator input and a vector of complex gains computed by the linearity adaptation circuit based on a feedback signal indicative of PA's output. The adaptation circuit is configured to compute the vector of complex gains in a manner that maximizes the power of the actuator output while ensuring that the deviation of PA's behavior from a linear behavior (e.g., in terms of one or more linearity parameters) is below a threshold. Controlling actuator output in a manner that maximizes its power while taking into consideration one or more linearity parameters to ensure that target linearity is achieved controls drive signals for the PA and, thus, may help in terms of PA linearity and efficiency.

Linearity optimizer for a millimeter-wave beamforming system

Digital predistortion (DPD) arrangements that use coding to differentiate between contributions from individual power amplifiers (PAs) is disclosed. When used with a phased antenna array having N antenna elements and N corresponding PAs, the arrangements may sequentially apply N codes to input signals provided to N PAs. Each code is a vector having N elements, where each element corresponds to a different PA in that the element is a complex gain applied to an input signal for the PA. Together, the N codes may be arranged as N rows or N columns of a matrix P. The disclosed arrangements may generate N feedback signals by applying the matrix P to a signal generated by a probe antenna element sensing wireless RF signals transmitted by the N antenna elements, and to update DPD coefficients based on the N feedback signals. The N codes may be either orthogonal or non-orthogonal.

Digital predistortion using coding for phased antenna arrays

Otherwise incompatible crest factor reduction (CFR) and cable tilt compensation can be used together, such as in a cable television or other cable communication system having a frequency-dependent signal loss at higher frequencies. The CFR can be used to limit or reduce peaks of signals provided to a power amplifier, while additional tilt reference and tilt equalizer circuits are included to address deleterious peak regrowth effects that may otherwise arise by using conventional CFR together with cable tilt compensation.

Crest factor reduction in cable communication systems

An example communication system includes a frequency-segmented power amplifier (PA) circuit that includes a plurality of PA segments. Each PA segment is configured to amplify a portion of a PA input signal in a different frequency band to generate a respective output signal (PA segment output signal). The frequency-segmented PA circuit further includes a combiner, configured to combine PA segment output signals from different PA segments to provide a power-amplified version of the PA input signal. Implementing such a frequency-segmented PA circuit may result in significant improvement in PA efficiency.

Frequency-segmented power amplifier

Various examples are directed to a power amplifier circuit, comprising a digital predistortion circuit, first and second power amplifiers, and a bias feedback circuit. The digital predistortion circuit may be configured to generate a predistorted input signal based at least in part on an input signal. The first power amplifier may be configured to generate a first amplified signal based at least in part on the predistorted input signal. The second power amplifier may be configured to generate a second amplified signal based at least in part on the predistorted input signal. The bias feedback circuit may be configured to adjust at least one of a bias of the first power amplifier or a bias of the second power amplifier to align a first nonlinear behavior of the first power amplifier with a second nonlinear behavior of the second power amplifier.

Digital predistortion for multiple power amplifiers

Transmitter noise cancellation may be applied on a channel by channel basis to active channels of an incoming radio frequency signal received at a receiver. A noise cancellation filter may be provided for each active channel in a predetermined signal band. Applying noise cancellation on a per active channel basis instead of to the entire receive band may substantially reduce the filtering requirement and number of filter coefficients or taps to save power and reduce manufacturing costs. Channelized transmitter noise cancellers, multi transmitter-receiver cross coupling cancellers, and hybrid full signal band and channelized transmitter noise cancellers are also provided.

Radio frequency transmitter noise cancellation

Growing community of inventors

Mallow, Ireland

Patrick Joseph Pratt