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All Journal EMITTER International Journal of Engineering Technology Indonesian Journal of Electrical Engineering and Computer Science
Yatnalli, Veeramma
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Computer Science & IT

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Comparative efficiency analysis of RF power amplifiers with fixed bias and envelope tracking bias Babu, Ambily; Shivaleelavathi, Bangalore Gangadharaiah; Yatnalli, Veeramma
Indonesian Journal of Electrical Engineering and Computer Science Vol 36, No 2: November 2024
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v36.i2.pp808-816

Abstract

RF power amplifier (RF PA) finds its application in almost all the areas of electronics, mobile communication being identified as a major area. The paper performs a comparative efficiency analysis of RF power amplifiers operating with a fixed bias and an envelope tracking bias. Simulations are performed using Keysight advanced design system (ADS) tool. A class a RF PA operating at a 12 dB gain is fixed for the work. 16 QAM LTE signal operating at 5 MHz input frequency, with a peak to average power ratio (PAPR) of 6.0 dB is used as input signal. An envelope simulation at 2.5 GHz is performed on the RF power amplifier. Simulation result shows an improvement of 12% in power added efficiency (PAE) at 6 dB back-off and 6.422% in mean PAE while using envelope tracking power amplifiers, compared to RF PA with fixed supply. Envelope tracking power amplifiers reduced AM/AM distortions also by a factor of 0.248. The results obtained are much better than that obtained using a conventional RF PA with fixed bias. RF PA being the most power dissipative block in a mobile handset, improving its efficiency contributes directly to a great improvement in the battery lifetime of mobile phones. The major challenges faced by envelope tracking PA (ETPA) designers in achieving this efficiency improvement is also delineated in the paper.
Review on Multi Level Inverter Topologies and Control Strategies for Solar Power Conversion Shivaleelavathi, B. G.; Srikanth, Chinmayi; Yatnalli, Veeramma
EMITTER International Journal of Engineering Technology Vol 8 No 2 (2020)
Publisher : Politeknik Elektronika Negeri Surabaya (PENS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24003/emitter.v8i2.500

Abstract

Nowadays solar power has become an alternate method of power generation for standalone systems for both urban and rural electrification. The Power Electronics converters used for the power conversion should provide quality AC output to have near sinusoidal voltage. The inverter topology and the PWM technique of the inverter play a vital role in providing quality output. This paper reviews recent contribution to establish the current status and development of the technology to provide reader with an insightful review of multilevel inverters and its control strategy. A brief overview of Multi Level Inverters (MLI) topology and advantages of Cascaded H-Bridge Multi Level Inverter (CHBMLI) for solar power conversion is presented and the various control strategies for CHBMLI are discussed with view point of quality output. Among the different PWM techniques discussed, the Elliptical Multi Carrier PWM (EMC PWM) control strategy is the new modulation technique which successfully improves the DC bus utilization without over-modulation and without adding third harmonic to fundamental frequency. Also, the technique is successful in reducing the %THD at the output voltage. The control strategy is simple even with increased level of output voltage, which is not possible in SVPWM technique. Hence, the EMC PWM technique is having better performance when compared to Multi Carrier PWM (MCPWM) technique, Space Vector PWM (SVPWM) technique and Third Harmonic Injection PWM (THIPWM) technique.
Co-Authors Babu, Ambily Shivaleelavathi, B. G. Shivaleelavathi, Bangalore Gangadharaiah Srikanth, Chinmayi