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This paper describes a new design approach for a power amplifier (PA) of the highly efficient hybrid envelope elimination and restoration (H-EER) transmitter. Since the PA operates mostly at the average power region of the modulation signal, power-added efficiency (PAE) of the PA at the average drain voltage is very important for the overall transmitter(More)
A saturated Doherty amplifier based on class-F amplifiers is analyzed in terms of its load modulation behavior, efficiency, and linearity. Simulations included the amplitude ratio and phase difference between the fundamental and third harmonic voltages, the current/voltage waveforms, load lines, and the third-order intermodulation amplitudes/phases of the(More)
We demonstrate an optimized design of a highly efficient three-stage Doherty power amplifier (PA) for the 802.16e mobile world interoperability for microwave access (WiMAX) application at 2.655 GHz. The “three-stage” Doherty PA is the most efficient architecture among the various Doherty PAs for achieving a high peak to average power ratio(More)
We have proposed a simple and effective weighted polynomial digital predistortion algorithm, which consists of weighting, least square polynomial fit, and de-weighting. The weighting factor is introduced to describe the signal distribution statistics and high harmonic generation at a high power region to improve accuracy of the error function. A low memory(More)
A total of 140 weaning pigs ((Landrace×Yorkshire)×Duroc, BW = 6.47±0.86 kg) were used in a 5-wk growth trail to determine the effects of phytoncide supplementation on growth performance, nutrient apparent total tract digestibility (ATTD), blood profiles, diarrhea scores and fecal microflora shedding. Pigs were assigned randomly by BW into 5 treatments,(More)
We have developed a new adaptive digital predistortion (DPD) linearization technique based on analog feedback predistortion (FBPD). The lookup-table-based feedback input can remove the bandwidth limitation of the feedback circuit related to the loop delay, and suppress feedback oscillation by accurate digital control of the feedback signal. Moreover, the(More)
This paper presents an approach to maximize the efficiency of a Doherty power amplifier (PA) with the knee voltage effect. Since the carrier PA with , which is the usual matching impedance for a carrier PA at a low power region, does not reach to the saturated operation at the 6-dB back-off power level, the maximum efficiency could not be achieved. However,(More)
A saturated power amplifier (PA) optimized for efficiency is described. As a PA is driven into saturated operation, the current source of the device generates a large third harmonic current, which creates a quasi-rectangular current waveform. The large nonlinear output capacitor of the transistor generates a second harmonic voltage with a very small third(More)
This paper describes a 16-bit programmable xed-point digital signal processor, called MDSP-II, for mobile communication applications. The instruction set of MDSP-II was determined after a careful analysis of the GSM Global System for Mobile communications baseband functions. An application-speciic hardware block called MCA Mobile Communication Accelerator(More)