Patent
Variable bandwidth envelope modulator for use with envelope elimination and restoration transmitter architecture and method
TLDR
In this paper, an envelope elimination and restoration (EER) RF transmitter includes at least one power RF amplifier having the input terminal for receiving the phase modulated signal to be transmitted on the RF carrier, and further including an input power node for receiving a modulated voltage for amplitude modulating the RF ''carrier''.Abstract:
A RF transmitter has at least one amplifier having an input terminal for receiving a phase modulated signal to be transmitted on an RF carrier and an input node for receiving a modulation signal for amplitude modulating the RF carrier. The RF transmitter further includes an amplitude modulator having an output coupled to the input node of the power amplifier through a low-pass filter. The low-pass filter includes at least one variable filter component for varying a bandwidth of the low-pass filter. In a preferred embodiment an envelope elimination and restoration (EER) RF transmitter includes at least one power RF amplifier having the input terminal for receiving the phase modulated signal to be transmitted on the RF carrier, and further including an input power node for receiving a modulated voltage for amplitude modulating the RF `carrier. The EER RF transmitter further includes a class-S modulator having a variable bandwidth low-pass filter having an output coupled to the input power node and including at least one first variable capacitance.read more
Citations
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Patent
Power supplies for rf power amplifier
TL;DR: In this article, a switchmode power supplies (SMPSs) and their control methods for radio frequency (RF) power amplifiers in bat- tery-powered wireless transmitter devices are described.
Patent
Group delay calibration method for power amplifier envelope tracking
Nadim Khlat,Karl F. Horlander +1 more
TL;DR: In this article, an open loop envelope tracking system calibration technique and circuitry is proposed, where an envelope tracker power converter generates a modulated power amplifier supply voltage for the radio frequency power amplifier based on a control signal derived from the modulated signal.
Patent
Apparatuses and methods for rate conversion and fractional delay calculation using a coefficient look up table
TL;DR: In this paper, a system and method for performing sample rate conversion and creating fractional delays to a signal is described, which consists of a filter, a look-up table for storing coefficients for sampling rate conversion, and control circuitry configured to use an indexing scheme to select one or more coefficients from the look up table for rate conversion.
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Pseudo-envelope following power management system
Nadim Khlat,Michael R. Kay +1 more
TL;DR: In this article, a pseudo-envelope follower power management system was used to manage the power delivered to a linear RF power amplifier, which is used to control a linear power amplifier.
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Power loop control based envelope tracking
TL;DR: In this article, the transceiver circuitry regulates a modulated power supply voltage, which is used by the radio frequency power amplifier to provide power for amplification, based on the difference between the target output power from the RFP amplifier and the measured output power of the RF power amplifier.
References
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Journal ArticleDOI
L-band transmitter using Kahn EER technique
TL;DR: In this paper, a 20-W peak-envelope power linear L-band transmitter based upon the Kahn envelope-elimination-andrestoration technique is described, which achieves an efficiency of 56% at full power (41 dBm), and 35% at 18 dB into back-off.
Patent
Power- conserving drive-modulation method for envelope-elimination-and-restoration (EER) transmitters
TL;DR: In this paper, a method and a circuit for high-efficiency linear RF-power amplification over a wide range of amplitudes from zero to peak output includes a final RF power amplifier operating at or near saturation, an RF driver amplifier, a high-level amplitude modulator for the final amplifier, and a means for determining the supply-voltage input to the final amplifiers and for controlling the amplitude of the drive.
Journal ArticleDOI
Bandpass delta-sigma class-S amplifier
M. Iwamoto,A. Jayaraman,G. Hanington,P.F. Chen,A. Bellora,W.T. Thornton,Lawrence E. Larson,Peter M. Asbeck +7 more
TL;DR: In this article, a class-S amplifier with a bandpass delta-sigma modulated input was demonstrated using CMOS devices at 10 MHz, with an output power of 26 dBm and a drain efficiency of 33%.
Patent
Method and apparatus for high efficiency wideband power amplification
TL;DR: In this article, an envelope detector (220), an interleaved class S modulator (270), and a power amplifier (260) are used for efficient power amplification of a wideband signal with a correspondingly wide modulation bandwidth.
Patent
Broadband multicarrier amplifier system and method using envelope elimination and restoration
TL;DR: In this paper, an amplifier system (100) for transmitting wideband multicarrier communication signals in a satellite communication system uses wideband envelope elimination and restoration amplifiers (200) upconverts channelized IF signals to provide a wideband multi-channel RF output signal between 20 and 30 GHz having a bandwidth between 100 and 200 MHz.