An overview of digital predistortion techniques for microwave power amplifier linearization is here presented. Different predistortion approaches are considered, and both static and dynamic (memory effects) behavioral models are presented. Special focus is done to the most suitable solutions for facing the new challenge to linearize high-bandwidth amplifiers, as demands most of the new telecomm...

In this paper, large-signal intermodulation distortion (IMD) sweet spots in microwave power amplifiers are studied and predicted using a new mathematical basis. The variations in the IMD versus drive pattern with active bias point and the terminating matching networks are investigated. This nonlinear distortion model enabled the design of power amplifiers specially tailored to present a desired...

A trade-off between linearity and efficiency exists in conventional power amplifiers. The outphase amplifying concept overcomes this trade-off by enabling the use of high efficiency, non-linear power amplifiers for linear amplification. An amplitude modulated signal is first decomposed into two constant amplitude, phase modulated signals that can be amplified using two high efficiency switching...

A Class-E/Fodd high power amplifier (PA) using the distributed active transformer (DAT) is demonstrated at 29MHz. The DAT combines the output power from four VDMOS push-pull pairs. The zero voltage switching (ZVS) condition is investigated and modified for the Class-E/Fodd amplifier with a non-ideal output transformer. All lumped elements including the DAT and the transistor package are modeled...

Abstract In this paper a promising novel output voltage filtering concept for multi-cell switch-mode power amplifiers is analyzed. The proposed hybrid filtering concept is based on a passive LC filter enhanced by a linear-mode correction stage of small rated power. Using this principle, also "sub-harmonic" (i.e. low-frequency) switching noise distortions (typically appearing in real interleaved...

A novel ballast resistor network is proposed to achieve a better thermal management in HBT power cells without degrading the RF performances. Experiments were conducted on two HBT power amplifiers. They occupy same area. One was designed using conventional ballast network. The other uses proposed novel network. Temperature comparisons were made based on the same current density. Infrared camera...

We present a simple semianalytical model of thermally induced mode coupling in multimode rare-earth doped fiber amplifiers. The model predicts that power can be transferred from the fundamental mode to a higher-order mode when the operating power exceeds a certain threshold, and thus provides an explanation of recently reported mode instability in such fiber amplifiers under high average-power ...

This paper proposes a robust combination of digital predistortion (DPD) and crest factor reduction (CFR) for radio frequency (RF) power amplifiers (PAs). It is constructed using the architecture of CFR-DPD connected with a compensation module (CM). The compensation module is introduced to achieve mutual compensation between the output signals of CFR and DPD, and this can reduce the damage to th...

Class-E power amplifiers have high efficiency, which makes them attractive in modern wireless mobile communication systems. There are several techniques and approaches developed solely to design the output load networks of such amplifiers to shape the RF power device’s output voltage and current for minimum power loss. However, little attention is brought to the design of the input matching net...