volume | PIER Journals

Abstract

Two parallel dipoles are assessed for antenna diversity. The three-dimensional radiation pattern is considered for signals correlation coefficient. The pattern analysis reveals that, depending on dipole spacing, three types of diversity techniques are generated: space, amplitude-pattern and phase-pattern diversity. The weighting of each technique in signals correlation coefficient mitigation is investigated. The results show that for closely spaced dipoles, the generated phasepattern diversity is the most dominant factor which greatly reduces the signals correlation coefficient. The diversity configuration is measured in a rich scattering environment. Results include signals correlation coefficient, diversity gain for selection combining and maximum ratio combining, effective diversity gain and antenna radiation efficiency can be demonstrated. We show that in rich multipath channel the minimum spatial distance, for effective diversity gain performance, is reduced from 0.5Î» for uncoupled dipoles to 0.15Î» for coupled dipoles.

1. Parson, J. D., The Mobile Radio Propagation Channel, second edition, 2000.

2. Vaughan, R., "Spaced directive antennas for mobile communications by the Fourier transform method," IEEE Trans. on Antennas and Propagat., Vol. 48, No. 7, 1025-1032, 2000.
doi:10.1109/8.876319

3. Balanis, C. A., Antenna Theory: Analysis and Design, Wiley, 1997.

4. Khaleghi, A.A. Azoulay, and J. C. Bolomey, "Diversity techniques with dipole antennas in indoor multipath propagation," 16th Annual IEEE International Symposium on Personal Indoor and Mobile Radio Communication (PIMRC), No. 9, 2005.

5. Vaughan, R. G. and J. B. Andersen, "Antenna diversity in mobile communications," IEEE Trans. on Vehicular Technology, Vol. 36, No. 4, 149-172, 1987.

6. Hui, H. T., W. T. O. Yong, and K. B. Toh, "Signal correlation between two normal-mode helical antennas for diversity reception in a multipath environment," IEEE Trans. Antennas and Propagat., Vol. 52, No. 2, 572-577, 2004.
doi:10.1109/TAP.2004.823950

7. Brown, T. W. C.S. R. Saunders, and B. G. Evans, "Analysis of mobile terminal diversity antennas," IEE Proceedings, Vol. 152, No. 2, 2005.

8. Wallace, J. W. and M. A. Jensen, "Termination-dependent diversity performance of coupled antennas: network theory analysis," IEEE Trans. Antennas and Propagat., Vol. 52, 98-105.
doi:10.1109/TAP.2003.822444

9. Boyle, K., "Radiation patterns and correlation of closely spaced linear antennas," IEEE Trans. Antennas Propagat., Vol. 50, No. 8, 1162-1165, 2002.
doi:10.1109/TAP.2002.801367

10. Jensen, M. A. and Y. Rahmat-Samii, "Performance analysis of antennas for hand-held transceivers using FDTD," IEEE Trans. Antennas Propagat. Vol. 42, Vol. '' IEEE Trans. Antennas Propagat. 42, No. 8, 1106-1113, 1994.
doi:10.1109/8.310002

11. Leifer, M. C., "Signal correlations in coupled cell and MIMO antennas," Proc. IEEE Antennas and Propagat. Society Int. Symp., Vol. 3, No. 6, 194-197, 2002.

12. Svantesson, T. and A. Ranheim, "Mutual coupling effects on the capacity of multi-element antenna systems," Proc. IEEE ICASSP'2001, Vol. 4, No. 5, 2485-2488, 2001.

13. Kildal, P.-S. and K. Rosengren, "Electromagnetic analysis of effective and apparent diversity gain of two parallel dipoles," IEEE Antennas and Wireless Propagat. Letters, Vol. 2, No. 4, 2003.

14. Rosengren, K. and P.-S. Kildal, "Radiation efficiency, correlation, diversity gain, and capacity of a six monopole antenna array for a MIMO system: Theory, simulation and measurement in reverberation chamber," Proceedings IEE, Vol. 152, No. 1, 7-16, 2005.

15. Rosengren, K. and P.-S. Kildal, "Study of distribution of modes and plane waves in reverberation chamber for characterization of antennas in multipath environment," Microwave and Optical Technology Letters, Vol. 30, No. 20, 386-391, 2001.
doi:10.1002/mop.1323

16. Khaleghi, A.J. C. Bolomey, and A. Azoulay, "On the statistics of the reverberation chambers and application for wireless antenna test," IEEE symposium on the Antennas and Propagation (AP-S), No. 7, 2006.

17. Taga, T., "Analysis for mean effective gain of mobile antenna in land mobile radio environments," IEEE Trans. on Vehicular Technology, Vol. 39, No. 2, 117-131, 1990.
doi:10.1109/25.54228

18. Douglas, M. G., M. Okoniewski, and M. A. Stuchly, "A planar diversity antenna for handheld PCS devices," IEEE Trans. on Vehicular Technology, Vol. 47, No. 3, 747-754, 1998.
doi:10.1109/25.704830

19. Glazunov, A., "Theoretical analysis of mean effective gain of mobile terminal antennas in Ricean channels," 56th IEEE Conference on VTC, Vol. 3, 1796-1800, 2002.

20. Clarke, R. H., "A statistical theory of mobile radio reception," Bell Syst. Tech. J., Vol. 47, 957-1000, 1969.

21. Scott, N. L., M. O. Leonard-Taylor, and R. G. Vaughan, "Diversity gain from a single-port adaptive antenna using switched parasitic elements illustrated with a wire and monopole prototype," IEEE Trans. Antennas and Propagat., Vol. 47, No. 6, 1066-1070, 1999.
doi:10.1109/8.777133

22. Mattheijssen, P., M. H. A. J. Herben, G. Dolmans, and L. Leyten, "Antenna-pattern diversity versus space diversity for use at handhelds," IEEE Trans.s on Vehicular Technology, Vol. 53, No. 7, 1035-1042, 2004.
doi:10.1109/TVT.2004.830156

23. Khaleghi, A.J. C. Bolomey, and A. Azoulay, "A pattern diversity antenna with parasitic switching elements for wireless LAN communications," 2nd IEEE International Symposium on Wireless Communication Systems 2005 (ISWCS2005), 2005.

24. Clarke, R. H., "A statistical theory of mobile-radio reception," Bell Syst. Tech. J., No. 7, 957-1000, 1968.

25. Jakes, W. C., Microwave Mobile Communications, IEEE Press, 1994.

26. Kouveliotis, N. K., P. T. Trakadas, and C. N. Capsalis, "FDTD modelling of a vibrating intrinsic reverberation chamber," Journal of Electromagnetic Waves and Applications, Vol. 17, 849-850, 2003.
doi:10.1163/156939303322503394

27. Musso, L., F. Canavero, B. Demoulin, and V. Berat, A Plane Wave Monte-Carlo Simulation Method for Reverberation Chamber, EMC Europe, 2002.

Dr. Ali Khaleghi