The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
권호 표지

I/Q Performance Analysis for IEEE 802.11 b/g VoWLAN Terminal with New Matching Circuit

새로운 정합회로를 적용한 IEEE 802.11 b/g VoWLAN 단말기에서의 I/Q 성능 분석

  • Published : 2007.01.31
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, the I/Q mismatch problem between the transmission line and antenna switch is solved by a new CPW matching circuit for a VoWLAN terminal with 54 Mbps communication speed through the IEEE 802.11 b/g CCK/OFDM. I/Q performances with the new matching circuit are analyzed and improved by the output spectrum mask, the characteristics of the EVM(Error Vector Magnitude) due to the nonlinear CCK/OFDM demodulation data, and receiver's sensitivity.

본 논문에서는 IEEE 802.11b/g 규격인 CCK/OFDM 방식의 54 Mbps 속도를 갖는 VoWLAN 단말기에서, RF 모듈을 통해 송수신되는 최종 전송선로(transmission line) 와 안테나 스위치단의 부정합으로 인해 쉽게 발생할 수 있는 입출력 사이의 I/Q 부정합 문제를 새로운 CPW 구조의 정합회로를 적용함으로써 해결할 수 있음을 보인다. I/Q 성능 개선에 대한 분석 방법으로 출력 Spectrum Mast 비선형 특성으로 출력된 CCK(complementary code keying)/OFDM(Orthogonal Frequency Division Multiplexing) 변조 데이터에 따른 EVM (Error Vector Magnitude) 특성 및 수신감도 특성을 분석하여 전체 I/Q 성능이 개선됨을 보인다.

Keywords

References

  1. IEEE Std. 802-11-1999, Part 11: Wireless Medium Access Control (MAC) and Physical Layer (PHY) specifications, IEEE 802.11 Std, 1999
  2. C. P. Wen, 'Coplanar Waveguide: A surface strip transmission line suitable for nonreciprocal gyromagnetic device application,' IEEE Trans. Microwave Theory Tech., vol.17, pp.1087-1090, Dec. 1969 https://doi.org/10.1109/TMTT.1969.1127105
  3. R. N. Simons, Coplanar Waveguide Circuits, Components, and Systems, Wiley-Interscience, 2001
  4. C. Y. Lee, 'The effects of the coupled slotline mode and air-bridges on CPW and NLC waveguide discontinuities,' IEEE Trans. Microwave Theory Tech., vol.43, pp.2759-2765, Dec.1995 https://doi.org/10.1109/22.475632
  5. K. C. Gupta, R. Garg, and I. Bahl, Microstrip Lines and Slotlines, Artech House, 1996
  6. R. W. Jackson, 'Consideration in the use of coplanar waveguide for millimeter wave integrated circuits,' IEEE Trans. Microwave Theory Tech., vol.34, pp.1450-1456, Dec.1986 https://doi.org/10.1109/TMTT.1986.1133562
  7. C. Veyres and V. F. Hanna, 'Extension of the application of conformal mapping techniques to coplanar lines with finite dimensions,' Int. J. Electron., vol.39, pp.239-246, 1991
  8. E. H. Fooks and R. A. Zakarevicius, Microwave Engineering Using Microstrip Circuits, Prentice Hall, 1990
  9. J. Heiskala and J. Terry, OFDM Wireless LANs : A Theoretical and Practical Guide, Sams Publishers, 2001
  10. F. L. Lin, S. F. Chen, L. F. Chen, and H. R. Chuang, 'Computer simulation and measurement of error vector magnitude (EVM) and adjacent-channel power ratio (ACPR) for digital wireless communication RF power amplifiers' Proc. IEEE Vehicular Technology Conf., vol.4, pp.2024-2028, Sept.1999
  11. M. Sagebiel, S. Gerlach, A. Kruck, and V. Subramanian, 'An EVM-optimized power amplifier for 2.4-GHz WLAN application.' Proc. Compound Semiconductor Integrated Circuit Symp., vol.1, pp.4, Nov.2005
  12. M. S. Heutmaker, 'The error vector and power amplifier distortion' Proc. Compound Semiconductor Integrated Circuit Symp., vol.1, pp.100-104, Aug.1997
  13. AP and VoIP Handset MFG Manufacturing Test suite IEEE 802.11a/b/g and draft 802.11n API Reference Manual Doc. No MV-S800364-00, Rev.B October 19, 2006