This article reviews trends, architectures, and recent developments in CMOS-based supply
modulators (SM) used for envelope-tracking power amplifiers (ET-PAs). This review details …

Apparatus and methods for envelope tracking are disclosed. In one embodiment, a power
amplifier system including a power amplifier and an envelope tracker is provided. The power …

An improved envelope amplifier architecture for envelope tracking RF power amplifiers is
presented, consisting of two switching amplifiers and one linear amplifier. The first switching …

Due to dynamic changes of supply voltage, envelope-tracking (ET) power amplifiers (PAs)
exhibit very distinct characteristics in different power regions. It is very difficult to compensate …

A hybrid supply modulator consisting of a parallel operation of a high-drive, low output
impedance, wideband class-AB linear amplifier and a high-efficiency, wideband, low-ripple …

This paper presents a fully integrated transformer-based Doherty power amplifier in a
standard 90 nm CMOS process. A novel asymmetrical series combining transformer is used …

This paper presents a CMOS RF power amplifier that employs a digital polar architecture to
improve the overall power efficiency when amplifying signals with high linearity …

This paper describes the analysis of an optimized envelope shaping function for the
envelope tracking power amplifier (ET PA) and its implementation. The proposed shaping …

This paper presents the realization of a linear polar transmitter supporting multistandard
applications. The harmonic-tuned class-AB biased (class-AB/F) power amplifier (PA) with …

A new supply modulator architecture for robust performance against the battery voltage
variation is presented. The resulting modulator is an optimized power management …