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
Citations
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Patent
Reducing effects of rf mixer-based artifact using pre-distortion of an envelope power supply signal
TL;DR: In this paper, a radio frequency (RF) power amplifier and an envelope tracking power supply are disclosed, where the RF PA receives and amplifies an RF input signal to provide an RF transmit signal using an envelope power supply signal, which at least partially envelope tracks the RF transmission signal, such that the input signal has an RF mixer-based artifact.
Patent
Quasi iso-gain supply voltage function for envelope tracking systems
TL;DR: In this paper, a method of defining a quasi iso-gain supply voltage function for an envelope tracking system is presented. But the method is not suitable for the case where the input power is a function of the input voltage.
Patent
Radio frequency power amplifier improvements using pre-distortion of an amplitude modulation power supply
TL;DR: In this paper, a pre-distortion of the AM signal is used to improve the linearity, the efficiency, or both, of the RF power amplifier, which may allow use of a reduced bandwidth predistorted AM signal to an AM power supply, and thus increase efficiency.
Patent
Using a switching signal delay to reduce noise from a switching power supply
TL;DR: In this paper, the power supply switching circuitry, which includes a first switching output signal to the first inductive element and a second switch output signal is delayed by a switching signal delay, is described.
Patent
Transitioning from envelope tracking to average power tracking
TL;DR: In this paper, an envelope tracking power supply and an offset capacitive element are disclosed, where the offset element is coupled between a switching output and an analog output of the ETS.
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.