Eta Devices, Inc.

Massachusetts Institute of Technology

Talkingheads Wireless, Inc.

Beth Israel Deaconess Medical Center, Inc.

Qorvo Us, Inc.

Ela Devices, Inc.

Joel L Dawson

David J Perreault

Mark A Briffa

Oguzhan Uyar

Krenar Komoni

John Edward DeRoo

Everest Huang

SungWon Chung

Philip Godoy

Yevgeniy A Tkachenko

Wei Li

Seward B Rutkove

John Hoversten

Nikolaus Klemmer

Frederick L Martin

Gangadhar Burra

Jeffrey Gengler

Mattias Astrom

Rached Hajjii

Amin Shahverdi

Elias Reese

Per-Ludvig B Normark

Mark Briffa

Balaji Lakshminarayanan

John E Deroo

Described are concepts, systems and techniques for dividing a communication channel such that no single radio frequency (RF) power amplifier (PA) in a remote radio head (RRH) operates over an excessively wide frequency bandwidth. This allows efficient operation of the RF PA wherein each PA transmit path is tuned for operation at a respective one of a plurality of different center frequencies (f, f+Δf, . . . f+(n−1)Δf where n is an integer corresponding to the number of RF PA transmit paths.

Cellular network that dynamically adjusts bandwidth and number of MIMO paths based on realized channel capacity

Described are concepts, systems and techniques for detecting whether an impedance mismatch exists at an output port of a remote radio head (RRH) or at an output port of a radio frequency (RF) amplifier in an RRH such as may be caused by a faulty connection between an antenna and a transmit signal path of the RRH. Also described are means for protecting an RF amplifier or other active RF device in the transmit signal path from damage due to such a faulty connection.

Sensing of antenna connection for remote radio heads

A power amplifier with a quasi-static drain voltage adjustment is provided that has a transistor that is made from Gallium Nitride (GaN). In an exemplary aspect, the transistor is a field-effect transistor (FET) having a source, gate, and drain. The transistor is tested for process variations. Based on detected process variations, a microcontroller may raise a drain voltage to increase output power capability. Power capability of the power amplifier scales as the square of the drain voltage, so small adjustments are sufficient to offset the slow process corner while maintaining reliability.

Power amplifier with quasi-static drain voltage adjustment

Described are concepts, systems and techniques for detecting whether an antenna is connected to a transmit system to thereby protect a power amplifier lineup from damage.

Systems and related techniques for efficient operation of a cellular network

A device for determining muscle condition of a region of tissue. The device comprises an electrical impedance myography (EIM) portable probe bearing an electrode array. The electrode array comprises excitation electrodes used to apply multi-frequency electrical signals to the region of tissue and pickup electrodes that are used to collect electrical signals resulting from the application of the multi-frequency electrical signals to the region of tissue. To improve accuracy and reproducibility of EIM measurements, the electrode array is reconfigurable to select different subsets of excitation and pickup electrodes so that the electrodes are oriented differently with respect to muscle fibers. Additional devices may be associated with the EIM probe to measure such parameters as temperature, moisture content of the region, quality of contact of electrodes of the electrode array with a surface of the region and pressure with which the EIM probe is applied to the region. The EIM measurements may be adjusted based on these parameters. Also, ultrasound and electrical impedance tomography measurements may supplement the EIM measurements for more complete analysis of the muscle condition.

Hand-held device for electrical impedance myography

Circuits and methods for achieving high linearity, high efficiency power amplifiers, including digital predistortion (DPD) and pulse cancellation in switched-state RF power amplifier systems are described.

Linearization circuits and methods for multilevel power amplifier systems

A radio frequency (RF) power amplifier system or transmitter includes one or more power amplifiers and a controller that is configured to adjust amplitudes and phases of RF input signals of the one or more power amplifiers and supply voltages applied to the one or more power amplifiers. In embodiments where multiple power amplifiers are used, a combiner may be provided to combine outputs of the power amplifiers.

RF amplifier having a transition shaping filter

A radio frequency (RF) transmit system includes an observation receiver coupled to receive a portion of an RF signal propagating along an RF transmit signal path and a digital pre-distortion (DPD) system coupled to the observation receiver and configured to receive one or more signals from the observation receiver and in response thereto, to adapt one or more DPD values of the RF transmit system over a period of time and a range of operating conditions of the RF transmit system and to provide one or more adapted DPD values to said controller.

Digital pre-distortion (DPD) training and calibration system and related techniques

A device for determining muscle condition of a region of tissue. The device comprises an electrical impedance myography (EIM) portable probe bearing an electrode array. The electrode array comprises excitation electrodes used to apply multi-frequency electrical signals to the region of tissue and pickup electrodes that are used to collect electrical signals resulting from the application of the multi-frequency electrical signals to the region of tissue. To improve accuracy and reproducibility of EIM measurements, the electrode array is reconfigurable to select different subsets of excitation and pickup electrodes so that the electrodes are oriented differently with respect to muscle fibers. Additional devices may be associated with the EIM probe to measure such parameters as temperature, moisture content of the region, quality of contact of electrodes of the electrode array with a surface of the region and pressure with which the EEM probe is applied to the region. The EIM measurements may be adjusted based on these parameters. Also, ultrasound and electrical impedance tomography measurements may supplement the ELM measurements for more complete analysis of the muscle condition.

A radio frequency (RF) amplification system or transmitter includes one or more power amplifiers and a controller that is configured to adjust amplitudes and phases of RF input signals of the one or more power amplifiers and supply voltages applied to the one or more power amplifiers. The system may include a single digital-to-RF modulator and a power divider to drive multiple power amplifiers. A power combiner may also be provided to combine outputs of the power amplifiers. In at least one implementation, amplitude adjustment of the RF input signals of the one or more power amplifiers may be used to provide transmit power control and/or power backoff.

Asymmetric multilevel backoff amplifier with radio-frequency splitter

Described embodiments provide a radio frequency (RF) amplifier system having at least one amplifier. The at least one amplifier includes an RF input port, an RF output port and a drain bias port. At least one voltage modulator is coupled to the bias port of the least one amplifier to provide a bias voltage. The bias voltage is selected by switching among a plurality of discrete voltages. At least one filter circuit is coupled between the at least one voltage modulator and the at least one amplifier. The at least one filter circuit controls spectral components resultant from transitions in the bias voltage when switching among the plurality of discrete voltages. A controller dynamically adapts at least one setting of the at least one voltage modulator by using multi-pulse transitions when switching among the plurality of discrete voltages for a first operating condition of the RF amplifier.

Linearity and noise improvement for multilevel power amplifier systems using multi-pulse drain transitions

Described embodiments provide an integrated power supply and modulator system. The system includes a magnetic regulation stage, a switched-capacitor voltage balancer stage, and at least one output switching stage. The switched-capacitor voltage balancer stage is coupled to an output of the magnetic regulation stage, and maintains a substantially ratiometric set of voltages with respect to a reference potential. The magnetic regulation stage includes an inductor and at least two switches to selectively couple the inductor to two or more of (a) an input of the magnetic regulation stage, (b) a first voltage node of the switched-capacitor voltage balancer stage, and (c) a second voltage node of the switched-capacitor voltage balancer stage. The output switching stage selectively couples at least two voltages from the switched-capacitor voltage balancer stage to an output of the system in response to control signals. The system may include startup circuitry, feedback/feedforward circuitry, and control circuitry.

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Roslindale, MA, United States of America

Joel L Dawson