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—Recent advances in the medical field are spurring the need for ultra-low power transceivers for wireless communication with medical implants. To deal with the growing demand for medical telemetry, the FCC commissioned the Medical Implant Communications Services (MICS) standard in 1999 in the 402–405 MHz band. This paper presents a 350 W FSK/MSK direct(More)
— We describe a new outphasing transmitter architecture in which the supply voltage for each PA can switch among multiple levels. It is based on a new asymmetric multilevel outphasing (AMO) modulation technique which increases overall efficiency over a much wider output power range than the standard LINC system while maintaining high linearity. For(More)
—This paper presents a 2.14-GHz, four-way power combining and outphasing system for high-power amplifiers such as those in radio basestations (RBS). The combiner is ideally lossless, and enables power control through load modulation of the power amplifiers (PAs). A discrete-component power combiner is designed and characterized, and combined with inverse(More)
—We describe a new outphasing energy recovery amplifier (OPERA) which replaces the isolation resistor in the conventional matched combiner with a resistance-compressed rectifier for improved efficiency. The rectifier recovers the power normally wasted in the isolation resistor back to the power supply, while a resistance compression network (RCN) reduces(More)
—We consider the problem of optimally allocating local feedback to the stages of a multistage amplifier. The local feedback gains affect many performance indexes for the overall amplifier , such as bandwidth, gain, rise time, delay, output signal swing, linearity, and noise performance, in a complicated and nonlinear fashion, making optimization of the(More)
—We demonstrate energy-efficient low-complexity adaptive linearization for wideband handset power amplifiers (PAs). Due to power overhead and complexity, traditional wideband linearization techniques such as adaptive digital pre-distortion (DPD) thus far have not been used for wideband handset transmitters. Our energy-efficient lookup table training(More)
—A phase-alignment system is used in the first reported IC to fully integrate a power amplifier, Cartesian feedback linearization circuitry, and a phase-alignment system. The phase-alignment system consumes 8.8 mW from a 2.5-V supply and employs a new technique for offset-free analog multiplication that enables it to function without manual trimming. Phase(More)