ETRI Journal, Volume 30, Number 1, February 2008 ABSTRACT⎯A highly linear and efficient GaN HEMT Doherty amplifier for wideband code division multiple access (WCDMA) repeaters is presented. For better performance, the adaptive gate bias control of the peaking amplifier using the power tracking circuit and the shunt capacitors is employed. The measured one-carrier WCDMA results show an adjacent ...

In brief, a dual-band doherty power amplifier employing reactance compensation with gallium nitride high-electron-mobility transistor technology is discussed. This design developed for long-term evolution (LTE) frequency operation, particularly the application of two-way radio to improve efficiency at back-off point from saturation output selected dual frequencies in LTE bandwidth. Measurements...

The power amplifiers are typically the most power-consuming block in wireless communication systems. Spectrum is expensive, and newer technologies demand transmission of maximum amount of data with minimum spectrum usage. This requires sophisticated modulation techniques, leading to wide, dynamic signals that require linear amplification. Although linear amplification is achievable, it always c...

This paper presents the design of a reconfigurable power amplifier for Mobile WIMAX applications in the user terminal. The amplifier, which operates from 3.4GHz to 3.5GHz, is based on the Doherty technique. This power efficiency enhancement technique is suitable for modern wireless communications systems, as Mobile WIMAX, that present with high peak-to-average power ratio (PAPR) to target high ...

Accurate FET Model parameters need to be determined to give accurate simulation results for RF amplifiers. The accuracy required varies depending on the application of the final amplifier. For Doherty amplifiers, a high accuracy is required for the transfer characteristic of the amplifier. An amplifier was simulated using a model obtained from data sheet information, and then built. Measurement...

This paper presents a novel and accurate procedure for designing Doherty power amplifier (DPA) wireless systems. The method is based on systematic approach to the matching networks of both Main Auxiliary devices, which employs an optimization process set their input impedance in corresponding optimal regions obtained from standard load- source-pull simulations. To import optimum each device int...

Doherty power amplifier (DPA) with high efficiency at the output back off is highly demanded for modern wireless communication systems to achieve data rates and reduce consumption operation costs. This paper presents a new design strategy enhancing DPA’s back-off efficiency. New called asymmetrical matching network used asymmetric operation, which helps compensate low delivered by peaking stage...

Radio signals typically are subject to very large transmission losses and distortions due to nonlinearities that might be added by the limited dynamic range of power amplifiers [1], [2]. Particularly, the signal gets distorted when the power amplifier is used at its full rated RF power level and/or Maximum efficiency is attained only at one single power level, usually closer to the maximum rate...