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
Modulated power supply system and method with automatic transition between buck and boost modes
Nadim Khlat,Michael R. Kay +1 more
TL;DR: In this paper, the authors present a modulated power supply system having a switching converter with an output terminal for supplying modulated powers to a load, which includes a controller adapted to transition the switching converter between a buck mode and a boost mode in response to a detection of at least one predetermined condition associated with the output terminal.
Patent
Cascaded converged power amplifier
TL;DR: In this article, a first radio frequency (RF) power amplifier (PA) stage, a second RF PA stage, and an alpha RF switch are disclosed, where the first PA stage provides a first RF output signal.
Patent
Monotonic conversion of rf power amplifier calibration data
TL;DR: In this paper, the data memory is used to store look-up table (LUT)-based radio frequency (RF) power amplifier (PA) calibration data, and processing circuitry converts at least a portion of the LUT-based RF PA calibration data to provide monotonic response curve-based data.
Patent
Transmitter utilizing a duty cycle envelope reduction and restoration modulator
TL;DR: In this paper, a broad power band transmitter utilizing a duty cycle modulator achieves 80dB of power range for 3G signals for mobile phones using a power amplifier operating in three different modes based upon the amplifier power level selected.
Patent
Dynamic loadline power amplifier with baseband linearization
TL;DR: In this paper, the authors describe a Doherty amplifier with a control circuit and a peaking RF amplification circuit, which is configured to activate the peaking circuit in response to the RF signal reaching a threshold level.
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.