Patent
Multi-mode amplifier system
Ian Stuart Robinson,Frank Winter +1 more
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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
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Patent
Amplifier efficiency tracking in digital envelope tracking system
TL;DR: In this paper, a method for generating a tracking supply voltage for a power amplifier is described, which includes: generating a plurality of supply voltages having a corresponding plurality of differing voltage levels; receiving a transmit signal indicative of a baseband transmit signal; generating a level select signal based on the transmit signal.
Patent
Multi-bandwidth envelope tracking integrated circuit and related apparatus
TL;DR: In this article, a multi-bandwidth envelope tracking (ET) integrated circuit (IC) and related apparatus are provided, in which the ET voltages are generated based on the modulation bandwidth of the RF signal.
Patent
Amplifier circuit having controllable output stage
Wen Sung-Han,Chen Ya-Chi +1 more
TL;DR: In this article, the authors proposed an amplifier consisting of a DAC, an output stage and a detector, where the DAC is used for performing digital-to-analog converting operation upon a digital input signal to generate an analog signal, and the output stage is used to receive the analog signal and generate an output signal.
Patent
Noise canceler and digital transmitter
TL;DR: In this article, a digital transmitter includes baseband interfaces to generate digital baseband signals with baseband frequencies, digital-upconverting stages to upconvert the baseband frequency to first radio frequencies having a predetermined frequency range, a M-band delta sigma M modulator to modulate the up-stage signals based on noise shaping and noise quantization processes, delay registers to align phases of the modulated upstage signals, a noise canceler to generate noise canceling signals with a converted polarity, a switch mode power amplifier to amplify the phase aligned modulated
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.