volume | PIER Journals

Abstract

This paper deals with the experimental validation of an effective near-field-far-field transformation technique with helicoidal scanning particularly suitable for electrically long antennas, whose validity has been numerically assessed in a previous authors' paper. Such a technique relies on the results relevant to the nonredundant sampling representations of the electromagnetic fields and makes use of an optimal sampling interpolation algorithm, which allows the reconstruction of the near-field data needed by the near-field-far-field transformation with cylindrical scan. The use of a prolate ellipsoid instead of a sphere to model an elongated antenna allows one to consider measurement cylinders with a diameter smaller than the antenna height, thus reducing the error related to the truncation of the scanning zone. Moreover, a significant reduction of the needed near-field data is also obtained. The comparison of the far-field patterns reconstructed from the acquired helicoidal measurements with those obtained from the data directly measured on the classical cylindrical grid assesses the effectiveness of the near-field-far-field transformation using this innovative scanning technique. At last, its validity is further confirmed by the very good agreement with the direct far-field measurements.

1. Yaghjian, A. D., "An overview of near-field antenna measurements," IEEE Trans. Antennas Propagat., Vol. 34, 30-45, January 1986.
doi:10.1109/TAP.1986.1143727 Google Scholar

2. Bucci, O. M., C. Gennarelli, G. Riccio, and C. Savarese, "Probe compensated NF-FF transformation with helicoidal scanning," Journal of Electromagnetic Waves and Applications, Vol. 14, No. 4, 531-549, 2000. Google Scholar

3. Bucci, O. M., C. Gennarelli, G. Riccio, and C. Savarese, "Nonredundant NF-FF transformation with helicoidal scanning," Journal of Electromagnetic Waves and Applications, Vol. 15, No. 11, 1507-1519, 2001.
doi:10.1163/156939301X00076 Google Scholar

4. Bucci, O. M., F. D'Agostino, C. Gennarelli, G. Riccio, and C. Savarese, "Probe compensated FF reconstruction by NF planar spiral scanning," IEE Proc. --- Microw., Ant. Prop., Vol. 149, 119-123, April 2002. Google Scholar

5. Bucci, O. M., F. D'Agostino, C. Gennarelli, G. Riccio, and C. Savarese, "NF-FF transformation with spherical spiral scanning," IEEE Antennas Wireless Propagat. Lett., Vol. 2, 263-266, 2003.
doi:10.1109/LAWP.2003.820710 Google Scholar

6. D'Agostino, F., F. Ferrara, C. Gennarelli, G. Riccio, and C. Savarese, "Directivity computation by spherical spiral scanning in NF region," Journal of Electromagnetic Waves and Applications, Vol. 19, 1343-1358, 2005.
doi:10.1163/156939305775525927 Google Scholar

7. D'Agostino, F., C. Gennarelli, G. Riccio, and C. Savarese, "Theoretical foundations of near-field-far-field transformations with spiral scannings," Progress In Electromagnetics Research, Vol. 61, 193-214, 2006.
doi:10.2528/PIER06021401 Google Scholar

8. Yaccarino, R. G., L. I. Williams, and Y. Rahmat-Samii, "Linear spiral sampling for the bipolar planar antenna measurement technique," IEEE Trans. Antennas Propagat., Vol. 44, 1049-1051, July 1996. Google Scholar

9. Bucci, O. M., C. Gennarelli, and C. Savarese, "Representation of electromagnetic fields over arbitrary surfaces by a finite and nonredundant number of samples," IEEE Trans. Antennas Propagat., Vol. 46, 351-359, March 1998.
doi:10.1109/8.662654 Google Scholar

10. Bucci, O. M., C. Gennarelli, and C. Savarese, "Fast and accurate near-field-far-field transformation by sampling interpolation of plane-polar measurements," IEEE Trans. Antennas Propagat., Vol. 39, 48-55, January 1991.
doi:10.1109/8.64434 Google Scholar

11. Gennarelli, C., G. Riccio, V. Speranza, and C. Savarese, "Fast and accurate interpolation of radiated fields over a cylinder," Progress In Electromagnetics Research, Vol. 8, 349-375, 1994. Google Scholar

12. Leach, Jr., W. M. and D. T. Paris, "Probe compensated NF measurements on a cylinder," IEEE Trans. Antennas Propagat., Vol. 21, 435-445, July 1973. Google Scholar

13. D'Agostino, F., F. Ferrara, C. Gennarelli, R. Guerriero, and M. Migliozzi, "Near-field-far-field transformation technique with helicoidal scanning for elongated antennas," Progress In Electromagnetics Research B, Vol. 4, 249-261, 2008.
doi:10.2528/PIERB08011503 Google Scholar

14. D'Agostino, F., F. Ferrara, C. Gennarelli, R. Guerriero, and M. Migliozzi, "The unified theory of near-field-far-field transformations with spiral scannings for nonspherical antennas," Progress In Electromagnetics Research B, Vol. 14, 449-477, 2009.
doi:10.2528/PIERB09031808 Google Scholar

15. D'Agostino, F., F. Ferrara, C. Gennarelli, R. Guerriero, and M. Migliozzi, "An effective NF-FF transformation technique with planar spiral scanning tailored for quasi-planar antennas," IEEE Trans. Antennas Propagat., Vol. 56, 2981-2987, September 2008.
doi:10.1109/TAP.2008.928786 Google Scholar

16. Costanzo, S. and G. D. Massa, "Far-field reconstruction from phaseless near-field data on a cylindrical helix," Journal of Electromagnetic Waves and Applications, Vol. 18, No. 8, 1057-1071, 2004.
doi:10.1163/1569393042955414 Google Scholar

17. Costanzo, S. and G. D. Massa, "Near-field to far-field transformation with planar spiral scanning," Progress In Electromagnetics Research, Vol. 73, 49-59, 2007.
doi:10.2528/PIER07031903 Google Scholar

18. Sten, J. C.-E. and E. A. Marengo, "Transformation formulas for spherical and spheroidal multipolefields," AEU Int. J. Electron. Commun., Vol. 61, No. 4, 262-269, 2007.
doi:10.1016/j.aeue.2006.04.005 Google Scholar

19. Bucci, O. M., G. D'Elia, and M. D. Migliore, "Advanced field interpolation from plane-polar samples: Experimental verification," IEEE Trans. Antennas Propagat., Vol. 46, 204-210, February. Google Scholar

20. D'Agostino, F., F. Ferrara, C. Gennarelli, G. Riccio, and C. Savarese, "NF-FF transformation with cylindrical scanning from a minimum number of data," Microw. Opt. Technol. Lett. , Vol. 35, 264-370, November 2002.
doi:10.1002/mop.10578 Google Scholar

Prof. Francesco D'Agostino

Dr. Flaminio Ferrara

Professor Claudio Gennarelli

Professor Rocco Guerriero

Dr. Massimo Migliozzi