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
Nonlinear compensation power amplification circuit and polar coordinate transmitter
Li Mingyuan,Wu Yue +1 more
TL;DR: In this paper, a nonlinear compensation power amplification circuit and a polar coordinate transmitter are presented, which consists of a polar coordinates signal generator, a digital-to-analog converter, a first filter, a second filter and a frequency mixer, a decoder and M groups of power amplifiers.
Patent
Efficient narrow band amplification using linear amplifier
TL;DR: In this paper, the output of the Class G Type amplifier is coupled to provide the VCC reference for the linear amplifier to obtain high frequency performance and high efficiency in an amplifier system with one or more signal paths.
Patent
Envelope tracking power amplifier module and envelope tracking method for the same
Mao Shau-Gang,Liou Chong-Yi,Wei-Ting Tsai,Chen Yu-Yao,Peng Zheng-An,Huang Shih-Ping,Chen Chien-Bang +6 more
TL;DR: An envelope tracking power amplifier module and an envelope tracking method are presented in this paper, where the power amplifier is configured to receive and amplify a signal according to the amplified envelope signal and outputting the amplified signal at the output power.
Patent
Power amplifier system and control method and control device thereof
TL;DR: In this article, a power amplifier system, a control method thereof, and a control device thereof are provided, which operates in a non-linear switching mode according to an envelope amplitude of an input signal under control of the control device.
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.