It has been shown that optimization of wireless network operations can be achieved by transmission power control of wireless nodes. Controlling the transmission power is mostly performed as a regulation of the final power amplifier, which is the major power sink. Depending on the desired transmission power level, currently popular amplifiers work at different levels of efficiency: highest in ca...

Energy-efficient, linear RF power amplifiers (PAs) are critical for achieving longer battery life in state-of-the-art radio transceivers because typically they determine and dominate the power consumption of the system. In this paper, an adaptive power management scheme using a novel dual-mode, noninverting, buck-boost converter targeted for code-division-multiple-access (CDMA) RF PA is present...

An approach for designing a beam-steering active phased array of antenna elements with integrated power amplifiers (PAs) is presented. It based on an amplifying unit cell (AiUC) concept, where the AiUC comprises radiating slot element, GaN high-electron-mobility transistor (HEMT), its input matching, and dc biasing/feeding circuitry. The HEMT embedded in being directly impedance-matched to HEMT...

This article proposes a new digital signal recovery (DSR) technique for next-generation power efficient low Earth orbit (LEO) satellite-to-ground communication systems, which feature additive white Gaussian noise (AWGN) channel and significant variation. utilizes the prior knowledge [i.e., nonlinearities of radio frequency amplifiers (RF-PAs)] space-borne transmitters to improve quality receive...

Conventional pipelined ADCs use electronic feedback to achieve highly linear and drift insensitive transfer characteristics in their interstage gain elements. Especially in the converter frontend, amplifiers with large open-loop gain are needed to achieve the desired accuracy. Due to additional, conflicting low noise and high bandwidth requirements, precision amplifiers dominate the power dissi...

Efficient Transmitters for Wireless Communications in Nanoscale CMOS Technology by Debopriyo Chowdhury Doctor of Philosophy in Engineering Electrical Engineering and Computer Sciences University of California, Berkeley Professor Ali M. Niknejad, Chair The last decade has witnessed a tremendous growth in wireless communications. Todays consumers demand wireless systems that are low-cost, power e...

Introduction. A method for designing power amplifiers use in the transmitting channels of X-band transceiver modules is investigated. The design process was aimed at optimizing relationship between basic amplifier characteristics, including operating frequency band, output level, linearity, high harmonics suppression, etc. Aim . Investigation a an UHF amplifier, which capable its main character...

We demonstrate the suppression of stimulated Brillouin scattering (SBS) in high power fiber amplifiers by a dual-single-frequency amplification. The output power of dualsingle-frequency fiber amplifiers in all-fiber configuration is boosted to 275 W with seeds central wavelength of 1063.7 and 1064.4 nm, respectively. The power conversion efficiency is 76.6%. The maximum output power is limited ...

The existing UHF Satellite Communications (SATCOM) transponders used for military applications use efficient, saturated power amplifiers, which provide one earth-coverage antenna beam. The amplifier is dedicated to small frequency band and only handles a few carriers simultaneously. The communications capacity needed to support future military forces on the move will require satellite payload p...

Due<span lang="EN-MY">to the high peak to average power ratio (PAPR) of modern modulated signals, amplifiers (PAs) have been forced operate at back-off (BO) region their saturation in order avoid signal clipping and distortion. However, classical PAs suffer from low efficiency BO operation. Therefore, has be enhanced that region. Many techniques proposed. Among them, Doherty amplifier (DP...