Journal of the Institute of Electronics Engineers of Korea TC (대한전자공학회논문지TC)

The Institute of Electronics and Information Engineers (대한전자공학회)
권호 표지

Analysis of Power Amplifier Phase Distortion Characteristics for IEEE 802.11a OFDM Wireless LAM Using Phase Predistortion

사전위상 왜곡을 이용한 IEEE 802.11a OFDM 무선랜 전력증폭기 위상왜곡 특성분석

  • Oh Chung Gyun (Dept. of Electronics Engineering, University of Incheon) ;
  • Choi Jae Hong (Dept. of Electronics Engineering, University of Incheon) ;
  • Koo Kyung Heon (Dept. of Electronics Engineering, University of Incheon)
  • Published : 2005.02.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, 2-stage power amplifier has been designed for 5.8GHz wireless LAN application. The power amplifier PldB output power has 21.6dBm at 5.8GHz frequency. Also the power amplifier shows 17.6dB gain and -17.8dB input return loss at 5.725GHz to 5.825GHz. The OFDM modulation and transmission block have been modeled in order to analyse the relationship between the power amplifier distortion and output ACPR for the IEEE 802.11a wireless LAN. The nonlinear characteristic of the power amplifier has been modeled as AM-to-AM and AM-to-PM using the behavioral model, and the output spectrum is analysed with the phase distortion variation. Also, amplifier back-off value from PldB to satisfy the required IEEE 802.11a standard spectrum mask has been simulated with phase distortion, and the simulation data have been compared to the measurement result collected by using the pre-distortion technique.

본 논문에서는 5.8GHz 무선랜에 적용할 수 있는 전력증폭기를 설계 및 제작하였다. 제작된 전력증폭기는 2단으로 구성되며 측정결과 중심주파수 5.8GHz에서 21.6dBm의 PldB 출력전력과 100MHz 대역에서 17.6dB 이득과 -17.8dB 이하의 입력반사손실을 얻었다. 설계된 전력증폭기의 왜곡과 출력 ACPR 관계를 분석하기위해, 최대 54Mbps의 전송속도를 가지는 IEEE 802.11a OFDM 변조부와 송신부를 모델링하였다. 전력증폭기의 비선형특성은 behavioral model을 이용하여 AM-to-AM과 AM-to-PM으로 모델링하였으며, 위상 왜곡에 따른 출력스펙트럼 특성을 해석하였다. IEEE 802.11a 무선랜 시스템의 요구 출력스펙트럼 마스크를 만족하기위한 PldB로부터 back-off값을 구하기 위하여 위상왜곡에 따른 전력증폭기의 ACPR 특성을 시뮬레이션하고 사전왜곡방식을 이용하여 증폭기의 위상왜곡을 변화시키며 측정한 결과와 시뮬레이션 특성을 비교 제시하였다.

Keywords

References

  1. Wireless LAN Medium Access Control(MAC) and Physical Layer specifications, IEEE Std. 802.11a/b/g, 1999/1999/2003
  2. S. Chen, W. Panton and R. Gilmore, 'Effects of Nonlinear Distortion on CDMA Communication Systems,' IEEE MTI-S Int. Microwave Symp. Dig., pp.775-778, 1996 https://doi.org/10.1109/MWSYM.1996.511053
  3. J. Sevic and J. Staudinger, 'Simulation of Power Amplifier Adjacent Channel Power Ratio for Digital Wireless Communication Systems,' IEEE MTI-S Int. Microwave Symp. Dig., pp.681-684, 1996 https://doi.org/10.1109/VETEC.1997.600415
  4. H. Gutierrez, K. Grad and M. Steer, 'Spectral Regrowth in Microwave Amplifier Using Transformation of Signal Statistics,' IEEE MTI-S Int. Microwave Symp. Dig., pp.985-998, 1999 https://doi.org/10.1109/MWSYM.1999.779551
  5. S. Cripps, RF Power Amplifiers for Wireless Communications, Arteeh House, 1999
  6. S. Mass, Nonlinear Microwave Circuitss, Arteeh House, 1998
  7. J. Vuolevi and T. Rahonen, 'Distortion in RF Power Amplifiers', Arteeh House Inc., Norwood, MA,2003
  8. R.. Minasian, 'lntermodulation Distortion Analysis of MESFET Amplifier Using Volterra Series Representation ,' IEEE Trans. Microwave Theory Tech., vol.28, pp.1-8, Jan.1980 https://doi.org/10.1109/TMTT.1980.1129998
  9. J. Sevic, K. Burger and M. Steer, 'A Novel Envelope Termination LoadPull Method for ACPR Optimization of RF/Microwave Power Amplifiers,' IEEE MTT-S Int. Microwave Symp. Dig., pp.723-726, 1998 https://doi.org/10.1109/MWSYM.1998.705093
  10. Wireless Lan Medium Acces Control (MAC) and Physical Layer (PHY) Specifications, IEEE Computer Society,July 1996
  11. M. Nishida, S. Murai, H. Uda, H. Tominiga, T. Sawai and A Ibaraki, 'A High Efficiency GaAs Power Amplifier Module with a Single Voltage for Digital Cellular Phone Systems,' IEEE MTT-S Int. Microwave Symp. Dig., pp.743-746, 1997 https://doi.org/10.1109/MWSYM.1998.705028
  12. J.S. Park, S.R. Park, H.J. Roh and K.H.Koo, 'Power Amplifier Back-off Analysis with M-to PM for Millimeter-Wave OFDM Wireless LAN,' Proc. Of RAWCON2001, pp.189-192, 2001 https://doi.org/10.1109/RAWCON.2001.947603