Journal of the Institute of Electronics Engineers of Korea SD (대한전자공학회논문지SD)

The Institute of Electronics and Information Engineers (대한전자공학회)
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Circuit Parameter Optimization and Significantly Enhanced ACPR of W-CDMA Signals of Feedforward Analog Optical Transmitter through Systemetic Approach

시스템적 접근을 통한 피드포워드 아날로그 광 송신기의 회로 파라미터 최적화와 W-CDMA 신호의 ACPR 개선

  • Lee Joon-Jae (Microwave and Lightwave Telecommunication Lab., Chung-ang univ.) ;
  • Park Sang-Hyun (Microwave and Lightwave Telecommunication Lab., Chung-ang univ.) ;
  • Yun Young-Seol (Samchully Co., Ltd) ;
  • Moon Yon-Tae (Microwave and Lightwave Telecommunication Lab., Chung-ang univ.) ;
  • Choi Young-Wan (Microwave and Lightwave Telecommunication Lab., Chung-ang univ.)
  • 이준재 (중앙대학교 전자전기공학부) ;
  • 박상현 (중앙대학교 전자전기공학부) ;
  • 윤영설 ((주)삼천리) ;
  • 문연태 (중앙대학교 전자전기공학부) ;
  • 최영완 (중앙대학교 전자전기공학부)
  • Published : 2006.05.01
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Abstract

The optical feedforward is known as a complicated technique in spite of its superior linearization. Here we optimized the feedforward circuit parameters using a systematic approach for optimum efficiency. A systematic approach was verified by transmission experiments of 2.14 GHz two tones. The compared third order IMD was enhanced by 38 dB for two-tone case. The experimental results for transmission of W-CDMA signals were described. The ACPR was enhanced by 20 dB for 1 W-CDMA carrier and by 16 dB for 3 W-CDMA carriers. Also, noise level was reduced by 7 dB.

광 피드포워드 방식은 높은 선형성을 가졌지만 시스템 구성이 매우 복잡한 기법으로 알려져 왔다. 본 논문에서는 최적의 효율을 위해 시스템적으로 접근하여 피드포워드 회로 파라미터들을 최적화하였고, 이 시스템적인 접근 방식을 통해 2.1 GHz 투톤 실험에서 3차 상호변조왜곡 성분이 38 dB 개선됨을 확인하였다. W-CDMA 입력신호에 대한 ACPR 측정 실험에서 중심주파수가 2.14 GHz인 1 carrier W-CDMA 신호를 입력하였을 때 20 dB, 3 carriers W-CDMA 신호의 입력에서는 16 dB가 각각 개선되었다. 또한 주 신호와 왜곡 신호가 정확히 정합되었을 때, $2.09^{\sim}2.26\;GHz$의 주파수 영역에서 최대 7 dB의 잡음레벨이 상쇄됨을 확인하였다.

Keywords

References

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