• Title/Summary/Keyword: 포락선 추적 증폭기

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Study of Improved Efficiency Circuit for Envelope Tracking Amplifier in Cellular Radio Handset (샐룰러용 단말기의 포락선 추적 증폭기의 효율 개선회로에 관한 연구)

  • Jeong, Byeong-Koo;Kang, In-Ho;Sim, Jun-Hwan;Park, Dong-Kook;Kim, Joo-Yoen
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.9
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    • pp.44-50
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    • 2002
  • Recently, a envelope tracking(ET) amplifier that improves efficiency by changing of the bias according to the RF input level is presented to use for a high power amplifier of cellular radio handset using CDMA. The input and the output impedances of the ET amplifier may be varied by changing of the bias of the amplifier, and it makes the amplifier having low gain, low efficiency, and high input and output VSWR. In order to improve the input and the output mismatch of the amplifier, in this paper, two types of ET amplifier are suggested. In case of an ET amplifier using varactor diode, in experimentation, gain is improved about 7dB and the power consumption of the amplifier is better about 60% than that of the conventional amplifier. In case of a base voltage controlled ET amplifier, the gain and power consumption of the amplifier is improved about 9dB and 40% than those of the conventional amplifier, respectively.

Power Amplifier Module for Envelope Tracking WCDMA Base-Station Applications (포락선 추적 WCDMA 기지국 응용을 위한 전력증폭기 모듈)

  • Jang, Byung-Jun;Moon, Jun-Ho
    • Journal of Satellite, Information and Communications
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    • v.5 no.2
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    • pp.82-86
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    • 2010
  • In this paper, a power amplifier module for WCDMA base-station applications is designed and implemented using GaN field-effect transistors (FETs), which uses an envelope tracking bias system. The designed module consists of an high gain MMIC amplifier, a driver amplifier, a power amplifier, and bias circuits for envelope tracking applications. Especially, a FET bias sequencing circuit and two isolators are integrated for stable RF operations. All circuits are assembled within a single housing, so its dimension is just $17.8{\times}9.8{\times}2.0\;cm3$. Measured results show that the developed power amplifier module has good envelope tracking capability: the power-added efficiency of 35% at the output power range from 30dBm to 40dBm over a wide range of drain bias.

Asymmetric Saturated 3-Stage Doherty Power Amplifier Using Envelope Tracking Technique for Improved Efficiency (효율 향상을 위해 포락선 추적 기술을 이용한 비대칭 포화 3-Stage 도허터 전력 증폭기)

  • Kim, Il-Du;Jee, Seung-Hoon;Moon, Jung-Hwan;Son, Jung-Hwan;Kim, Jung-Joon;Kim, Bum-Man
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.8
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    • pp.813-822
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    • 2009
  • We have investigated operation of a 1:2:2 asymmetric 3-stage Doherty PA(Power Amplifier) and implemented using the Freescale's 4 W, 10 W PEP LDMOSFETS at 1 GHz. By employing the three peak efficiency characteristics, compared to the two peak N-way Doherty PA, the asymmetric 3-stage Doherty can overcome the serious efficiency degradation along the backed-off output power region and maximize the average efficiency for the modulation signal. To maximize the efficiency characteristic, the inverse class F PA has been designed as carrier and peaking amplifiers. Furthermore, to extract the proper load modulation operation, the adaptive gate bias control signal has been applied to the two peaking PAs based on the envelope tracking technique. For the 802.16e Mobile WiMAX(World Interoperability for Microwave Access) signal with 8.5 dB PAPR(Peak to Average Power Ratio), the proposed Doherty PA has shown 55.46 % of high efficiency at an average output power of 36.85 dBm while maintaining the -37.23 dB of excellent RCE(Relative Constellation Error) characteristic. This is the first time demonstration of applying the saturated PA and adaptive gate bias control technique to the asymmetric 3-stage Doherty PA for the highly efficient transmitter of the base-station application.

High Efficiency Power Amplifier Based on Digital Pre-Distortion (디지털전치왜곡 기반 고효율 전력증폭기 설계)

  • Kwon, Ki-Dae;Yoon, Wonsik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.8
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    • pp.1847-1853
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    • 2014
  • The PAPR of the input signal is increased due to OFDMA signal in a mobile communication system. High efficiency of a power amplifier, which accounts for power consumption, is a very important key technology. Digital Pre-Distortion techniques were used to improve the linearity of the power amplifier. The Asymmetric Doherty scheme was used to improve the efficiency of the power amplifier. In this paper, we propose a new structure of Asymmetric Doherty. Drive power amplifier part is separated as main path and peak path, and phase shifter is employed to improve power combine characteristics of the Doherty Amplifier. Also, envelope tracking technology for drive gate bais in drive peak amplifier is used to improve efficiency.