A hybrid method is developed to compute the radiation pattern of antennas on large complex three-dimension carriers. The hybrid method involves computing the radiation fields of the antenna in free space with FEM, characterizing the reflection and diffraction of the carrier to the radiation fields with CRE (Complex Ray Expansion) and UTD (Uniform Theory of Diffraction). The ray technique of SBR using traditional hybrid method is employed by CRE. The shortcomings of the SBR, such as great number of ray trace, distortion and partly shadowing of the rays etc., are overcome by the use of CRE, and the time consuming physical-optics-type integration is replaced by the paraxial approximation of the complex rays. A dipole placed on different carriers are taken as the examples to show the validity of the hybrid method, and the radiation patterns computed by the proposed method are in good agreement with those by FEM. By using the proposed method, the computation of the three dimension radiation pattern of an antenna in a large ship is finished by a PC in 1671.20 seconds.
2. Jin, J. M., The Finite Element Method in Electromagnetics, Wiley, New York, 1993.
3. Su, D. and D.-M. Fu, "Numerical modeling of active devices characterized by measured S-parameters in FDTD," Progress In Electromagnetics Research, Vol. 80, 381-392, 2008.
4. Keller, J. B., "Geometrical theory of diffraction," J. Opt. Soc. Am., Vol. 52, 116-130, 1962.
5. Lee, S. W., "Comparison of uniform asymptotic theory and Ufimtsev's theory of EM edge diffraction," IEEE Trans. on Antennas and Propagat., Vol. 25, 162-170, 1977.
6. Kouyoumjian, R. G. and P. H. Pathak, "A uniform geometrical theory of diffraction for an edge in a perfectly conducting surfaces," Proc. IEEE, Vol. 62, 1448-1461, 1974.
7. Zhang, Y., X. Zhao, M. Chen, and C.-H. Liang, "An efficient MPI virtual topology based parallel, iterative MOM-PO hybrid method on PC clusters," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 5, 661-676, 2006.
8. Chen, M., X.-W. Zhao, and C.-H. Liang, "Analysis of antenna around NURBS surface with iterative MoM-PO technique," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 12, 1667-1680, 2006.
9. Medgyesi-Mitschang, L. N. and D.-S. Wand, "Hybrid methods for analysis of complex scatterers," Proc. IEEE, Vol. 77, No. 5, 770-779, 1989.
10. Medgyesi-Mitschang, L. N. and D.-S. Wand, "Hybrid methods in computational eletromagnetics: A review," Computer Physics Communications, Vol. 68, No. 4, 76-94, 1991.
11. Medgyesi-Mitschang, L. N. and D.-S. Wand, "Hybrid solution for scattering from perfectly conducting bodies of revolution," IEEE Trans. on Antennas and Propagat., Vol. 34, 570-583, 1983.
12. Liu, H.-X., H. Zhai, L. Li, and C.-H. Liang, "A progressive numerical method combined with mon for a fast analysis of large waveguide slot antenna array," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 2, 183-192, 2008.
13. Nie, X.-C., Y.-B. Gan, N. Yuan, C.-F. Wang, and L.-W. Li, "An efficient hybrid method for analysis of slot arrays enclosed by a large radome," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 2, 249-264, 2008.
14. Mouysset, V., P. A. Mazet, and P. Borderies, "A new approach to evaluate accurately and efficiently electromagnetic fields outside a bounded zone with time-domain volumic methods," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 6, 803-817, 2008.
15. Guo, J., J.-Y. Li, and Q.-Z. Liu, "Analysis of antenna array with arbitrarily shaped radomes using fast algorithm based on VSIE," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 10, 1399-1410, 2008.
16. Li, X.-F., Y.-J. Xie, and R. Yang, "High-frequency method analysis on scattering from homogenous dielectric objects with electrically large size in half space," Progress In Electromagnetics Research B, Vol. 1, 177-188, 2008.
17. Yuan, N., X.-C. Nie, Y.-B. Gan, and T. S. Yeo, "Accurate analysis of conformal antenna arrays with finite and curved frequency selective surfaces," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 13, 1745-1760, 2007.
18. Greenwood, A. D. and J. M. Jin, "Hybrid FEM/SBR method to compute the radiation pattern from a microstrip patch antenna in a complex geometry," Proc. 1996 Antenna Appl. Symp., 1996.
19. Andersh, D., M. Hazlett, S. W. Lee, D. D. Reeves, D. P. Sullivan, and Y. Chu, "XPATCH: A high-frequency electromagnetic-scattering prediction code and environment for complex three-dimensional objects," IEEE Antennas Propagat. Mag.,, Vol. 36, 65-69, 1994.
20. Zhang, P.-F., Y.-X. Xu, and S.-X. Gong, "Complex rays expansion of three dimension radiation pattern using buckyball grid," IEEE 2007 International Symposium on Microwave, Antenna, Propagation, and EMC Technologies for Wireless Communications, 905-908, 2007.
21. Zhang, P.-F. and S.-X. Gong, "Fast Parallel calculation of the radar cross section for large open-ended cavities based on CRE and MPI," Journal of Xidian University, Vol. 34, No. 1, 82-86, 2007.
22. Wang, M., Geometry Theory of Diffraction, Xi'an Book Concern of Xidian University, 1994.