Patent
Multi-mode amplifier system
Ian Stuart Robinson,Frank Winter +1 more
TLDR
In this article, an amplifier system switches between modes of operation based upon a characteristic of an input signal relative to a first threshold level and a second threshold level, and a mode selector selects the operation mode by transmitting an amplitude modulated signal plus a variable headroom voltage to a supply terminal of a power amplifier during the envelope tracking mode, an amplitude and phase modulated input signal during the polar mode and a substantially constant amplitude signal to the supply terminal during the linear mode.Abstract:
An amplifier system is provided that switches between a linear mode of operation, an envelope tracking mode of operation and a polar mode of operation. The amplifier system switches between modes of operation based upon a characteristic of an input signal relative to a first threshold level and a second threshold level. A mode selector selects the operation mode by transmitting an amplitude modulated signal plus a variable headroom voltage to a supply terminal of a power amplifier during the envelope tracking mode, an amplitude modulated signal to the supply terminal and phase modulated input signal during the polar mode and a substantially constant amplitude signal to the supply terminal during the linear mode.read more
Citations
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Patent
RF power transmission, modulation, and amplification, including cartesian 4-branch embodiments
Patent
Dual-mode envelope tracking power converter circuitry
TL;DR: In this article, an envelope tracking power converter circuitry is configured to receive a supply voltage, an envelope control signal, and an average power tracking control signal and simultaneously provide an ECS power supply signal for amplifying a first radio frequency (RF) input signal based on the ECS signal.
Patent
Envelope tracking integrated circuit and related apparatus
TL;DR: In this article, an envelope tracking (ET) integrated circuit (IC) is provided, which is configured to generate an ET voltage based on a supply voltage and provide the ET voltage to an amplifier circuit for amplifying a radio frequency (RF) signal(s).
Patent
Adaptive Array Wireless Communication Apparatus and Method of Same
TL;DR: In this article, an adaptive array wireless communication apparatus able to suitably select antenna elements, small in amount of processing, fast in convergence speed, and suitable for transmission/reception, and a method of the same, which controls the directionalities of array antenna elements based on array weights, controls an antenna element selecting unit 23 so that the antenna elements are intermittently determined, and adjusts a period of determination of the antenna element based on information of antenna elements determined at a controlling unit 26.
Patent
3D frequency dithering for DC-to-DC converters used in multi-mode cellular transmitters
TL;DR: In this article, a DC-to-DC converter is modulated onto an RF carrier such that switching noise is spread over a given bandwidth that is wider than a communications measurements bandwidth.
References
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Journal ArticleDOI
High-efficiency power amplifier using dynamic power-supply voltage for CDMA applications
TL;DR: In this article, a boost DC-DC converter with an operating frequency of 10 MHz is demonstrated using GaAs heterojunction bipolar transistors, and an envelope detector circuit with a fast feedback loop regulator is discussed.
Patent
Method and apparatus for operating a radio-frequency power amplifier as a variable-class linear amplifier
TL;DR: In this paper, a variable-class linear amplifier (600, 800, 900) applies a supply type of envelope modulation to an RF power amplifier operating in or near compression at highest envelope amplitudes, and transitions gradually to an envelope tracking type of operation at intermediate amplifier amplitudes.
Patent
Method and apparatus for generating a linearly modulated signal using polar modulation
Bengt Lindoff,Hakan Eriksson +1 more
TL;DR: In this article, an apparatus and method for generating a linearly modulated signal in a polar modulation system is described, where a signal for transmission is separated into a phase component and an amplitude component, and a carrier signal is modulated with the phase component in a phase modulator, creating a phase distortion.
Patent
RF transmitter with extended efficient power control range
TL;DR: A highly efficient radio frequency (RF) transmitter provides both wide bandwidth and an extended power control range as mentioned in this paper, which is useful in wireless communications to increase both handset talk time and battery life.
Patent
Method, device, phone and base station for providing envelope-following for variable envelope radio frequency signals
Pallab Midya,Lawrence E. Connell,Steven F. Gillig,John Grosspietsch,Andrew Merritt Khan,George Francis Opas,Robert Louis Palandech +6 more
TL;DR: In this paper, an envelope-following unit is used to output a supply voltage in accordance with a variable envelope of an input baseband signal, wherein using the efficient envelope following unit includes: 1) using a bandwidth-limiting mapping unit to determine a reference signal based on the base band signal; and 2) using an envelope tracking power converter to output the supply voltage, responsive to the reference signal, to the linear RF power amplifier.