Journal of the Korea Convergence Society (한국융합학회논문지)

Korea Convergence Society (한국융합학회)
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Compensation of the Non-linearity of the Audio Power Amplifier Converged with Digital Signal Processing Technic

디지털 신호 처리 기술을 융합한 음향 전력 증폭기의 비선형 보상

  • Eun, Changsoo (Department of Radio Information Communications Eng., Chungnam National University) ;
  • Lee, Yu-chil (Kaidas Co., Ltd.)
  • Received : 2016.04.21
  • Accepted : 2016.05.18
  • Published : 2016.06.30
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Abstract

We propose a digital signal processing technic that can compensate the non-linearity inherent in audio amplifiers, and present the result of the simulation. The inherent non-linearity of the audio power amplifier arising from analog devices is compensated via a digital signal processing technic consisting of indirect learning architecture and an adaptive filter. The simulation results show that the compensator can be realized using a third-order polynomial and compensates odd-order non-linearity efficiently. The even-oder non-linearity is mainly due to the dc offset at the output, which is difficult to eliminate with the proposed method. Care must be taken in designing the bias circuit to avoid the DC offset at the output. The proposed technic has significance in that digital signal processing technic can compensate for the impairment that is an inherent characteristic of an analog system.

음향 전력 증폭기의 출력단에서 발생하는 비선형성을 보상하는 디지털 신호 처리 기술을 제안하고 그 모의실험 결과를 제시한다. 음향 전력 증폭기에 사용되는 소자에 의한 비선형성을 간접학습구조와 적응형 필터로 구성되는 디지털 신호 처리 기술로 보상한다. 적응형 필터를 사용함으로써 증폭기의 비선형 특성이 시간적으로 변하더라도 이를 적응적으로 보상할 수 있다. 모의실험 결과 전치 보상기는 3 차의 다항식으로 구현할 수 있으며 홀수차 비선형성을 효과적으로 제거할 수 있음을 보였다. 짝수 차 비선형은 출력 신호에 존재하는 직류 옵셋이 가장 큰 부분을 차지하며 이는 제안하는 기술로는 제거가 어려우므로 바이어스 회로 설계 시 유의해야 한다. 제안하는 기술은 아날로그 시스템의 본질적 특성 결함을 디지털 신호 처리 기술로서 보상할 수 있음을 보여준다.

Keywords

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