Journal of the Korean Institute of Telematics and Electronics A (전자공학회논문지A)

The Institute of Electronics and Information Engineers (대한전자공학회)
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A Study on Predistortor using the Feedforward type

Feedforward 방식을 이용한 Predistortor에 관한 연구

  • 권성준 (고등기술연구원 정보통신연구실) ;
  • 임성규 (동양전자통신㈜중앙연구소) ;
  • 최진일 (광운대학교 전자공학과) ;
  • 이상웅 (광운대학교 전자공학과) ;
  • 김상태 (생산기술연구원 기술관리본부) ;
  • 라극환 (광운대학교 전자공학과)
  • Published : 1994.05.01
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Abstract

A new Predistortor that is designed using Feedforward type is proposed to overcome the nonlinearity of HPA (High Power Amplifier). HPA has the nonlinearity of the gain compression and phase distorton, so digital communication system of multi-carrier TDMA needs the linear RF transmitter. Using IMD (Intermodulation Distortion) of drive amplifier, as Feedforward type, the inverse IMD is coupled to the main loop with variable attenuators, phase shifters, and sub-amplifiers well designed. At the input of main amplifier, the over-coupled IMD surpresses the main amplifier 's IMD. Adjusting the level and phase of IMD at the sub loop, C/I of HPA is better than before correction.

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