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
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Patent
Envelope tracking power supply voltage dynamic range reduction
Jean-Frederic Chiron,Nadim Khlat +1 more
TL;DR: In this article, the setpoint voltage of the power supply voltage is clipped to form clipped regions and substantially tracked the RF envelope between the clipped regions, wherein a dynamic range of the envelope tracking power supply voltages is limited.
Patent
Overlay class f choke
TL;DR: In this article, an overlay class F choke of a radio frequency (RF) power amplifier (PA) stage and an RF PA amplifying transistor of the RF PA stage is discussed, which includes a pair of mutually coupled class F inductive elements.
Patent
Voltage offset loop for a switching controller
Michael R. Kay,Nadim Khlat +1 more
TL;DR: In this paper, the RF filter is coupled to receive a pulsed output voltage from the RF switching converter and a supply voltage from a low-drop out (LDO) regulation circuit.
Patent
Apparatus and method for power management
TL;DR: An apparatus for power management for use in a mobile device includes an RF (Radio Frequency) circuit, a power amplifier, a processor, and a DC to DC (Direct Current to Direct Current) converter as discussed by the authors.
Patent
Temperature compensated bias for AM/PM improvement
TL;DR: In this paper, a system and method for maintaining a consistent operating condition of a power amplifier power amplifier across a range of operating temperatures is presented, where the power amplifier is provided with an input bias voltage (Vbias) that adjusts with temperature to compensate for the temperature dependent change of the power amplifiers base-emitter voltage drop Vbe.
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.