volume | PIER Journals

2004-04-15

Reduction of Errors in Antenna Radiation Patterns Using Optimally Truncated Spherical Wave Expansion

Paivi Koivisto

Dr. Paivi Koivisto

VTT Information Technology, Telecommunications

Finland

Homepage

, Vol. 47, 313-333, 2004

doi:10.2528/PIER03120301

Abstract

This paper demonstrates how the error of a measured or simulated antenna radiation pattern can be decreased by calculating a spherical wave expansion (SWE) with an optimised truncation mode index. Four radiation pattern examples are examined for which the analytical expression of the electrical field is known. Upon adding random and Î¦-alignment errors to the exact electric fields, the SWEs are determined and compared with the corresponding ones for the exact fields. These comparisons show that the accuracy of the calculated SWE is much better than the accuracy of the original inaccurate field. Resting on the calculated examples, a method is created which can be used to determine the optimal truncation index from the modal power distribution of a SWE without knowing the exact field. Finally, the method developed is applied to measured antenna radiation patterns.

Download Full Article (282) View Full Article volume

Citation

Copy Export

Paivi Koivisto, "Reduction of Errors in Antenna Radiation Patterns Using Optimally Truncated Spherical Wave Expansion," , Vol. 47, 313-333, 2004.
doi:10.2528/PIER03120301

References

1. Hansen, J. E. (Ed.), IEE Electromagnetic Waves Series 26: Spherical Near-Field Antenna Measurements, Peter Peregrinus Ltd., 1988.

2. Thal, H. L. and J. B. Manges, "Theory and practise for a sphericalscan near-field antenna range," IEEE Trans. on Antennas and Propagation, Vol. 36, No. 6, 815-821, 1988.
doi:10.1109/8.1183

3. Wiscombe, W. J., "Improved Mie scattering algorithms," Applied Optics, Vol. 19, No. 9, 1505-1509, 1980.

4. Koivisto, P. K., "Analytical solution for characteristic modal power distribution and truncation limit for spherical wave expansion of antenna radiation pattern," Journal of Electromagnetic Waves and Applications, Vol. 16, No. 9, 1307-1328, 2002.

5. IEEE Standard Test Procedures for Antennas, ANSI/IEEE Std 149-1979, ANSI/IEEE Std 149-1979, 149-1979, The Institute of Electrical and Electronics Engineers.

6. Leatherwood, D. A. and E. B. Joy, "Plane wave, pattern subtraction, range compensation," IEEE Trans. on Antennas and Propagation, Vol. 49, No. 12, 1843-1851, 2001.
doi:10.1109/8.982468

7. Dich, M. and H. E. Gram, "Alignment errors and standard gain horn calibrations," Proc. of the 19th Meeting and Symposium of the Antenna Measurement Technique Association, 17-21, 1997.

8. Black, D. N. and E. B. Joy, "Test zone field compensation," IEEE Trans. on Antennas and Propagation, Vol. 43, No. 4, 362-368, 1995.
doi:10.1109/8.376033

9. Jofre, L.E. B. Joy, and R. Wilson, "Antenna pattern correction for range reflections," Proc. AMTA, 1987.

10. Harrington, R. F., Time-Harmonic Electromagnetic Fields, Mc Graw-Hill, 1961.

11. Stratton, J. A., Electromagnetic Theory, 1 Ed., McGraw-Hill, , 1941.

12. Papas, C. H., Theory of Electromagnetic Wave Propagation, Dover Publications, Inc., , 1988.