Journal of the Korea Institute of Military Science and Technology (한국군사과학기술학회지)

The Korea Institute of Military Science and Technology (한국군사과학기술학회)
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A Study on Transmission Signal Design Using DAC to Reduce IQ Imbalance of Satellite-Mounted Synthetic Aperture Radar Transmitter

위성 탑재 영상레이다 송신기의 IQ 불균형 저감을 위한 DAC를 이용한 송신 신호 설계 기법에 관한 연구

  • Lee, Young-Bok (Defense and Space Technology Center, Agency for Defense Development) ;
  • Kang, Tae-Woong (Defense and Space Technology Center, Agency for Defense Development) ;
  • Lee, Hyon-Ik (Defense and Space Technology Center, Agency for Defense Development)
  • 이영복 (국방과학연구소 국방우주기술센터) ;
  • 강태웅 (국방과학연구소 국방우주기술센터) ;
  • 이현익 (국방과학연구소 국방우주기술센터)
  • Received : 2021.08.04
  • Accepted : 2022.03.21
  • Published : 2022.04.05
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Abstract

The on-board processor of satellite synthetic aperture radar(SAR) generates transmission signal by digital signal processing, converts it into an analog signal. At this time, the transmission signal generated from the baseband requires the frequency modulation to convert it to the high-frequency band in order to improve the stability. General frequency modulation method using local oscillator(LO) causes IQ imbalance due to phase error/magnitude error and these error reduce performance of SAR. To generate transmission signal without phase/magnitude error, this paper suggests design method of the frequency modulation method using digital to analog converter(DAC) at on-board SAR. For design, this paper analyzes the characteristic of DAC mode and uses pre-compensation filter. To analyze the proposed method performance, performance index are compared with IQ imbalance signals. This method is suitable for on-board SAR using fast sampling DAC and has the advantage of being able to solve IQ imbalances.

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References

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