An improved finite-difference time-domain (FDTD) method has been extended to analyze the antennas with complicated lumped/active networks in this paper. The improved FDTD method is based on a novel integral transform and the matrix theory. Combing the novel integral transform with Kirchhoff's circuit laws, the hybrid networks comprised of high order linear and nonlinear elements with arbitrary connection can be modeled by a stable matrix equation. An effective model is built for the linear lumped networks including the internal independent sources. A wire antenna loaded with wideband match network and a two-element active patch antenna loaded with Gunn diodes are analyzed by the developed techniques. The analysis results indicate that the improved matrix-type FDTD method is not only stable and accurate, but also time-saving in simulating the complicated hybrid networks.
2. Jin , J., The Finite Element Method in Electromagnetics, 2nd Ed., CRC Press, Boca Raton, FL, 2002.
3. Mittra, R., K. Du, and , "Characteristic basis function method for iteration-free solution of large method of moments problems," Progress In Electromagnetics Research B, Vol. 6, 307-336, 2008.
4. Xiao, S. Q., Z. H. Shao, M. Fujise, and B.-Z. Wang, "Pattern reconfigurable leaky-wave antenna design by FDTD method and Floquet's theorem ," IEEE Trans. Antennas Propag., Vol. 53, 1845-1848, May 2005.
5. Wang, M. Y., J. Xu, J.Wu, B.Wei, H.-L. Li, T. Xu, and D.-B. Ge, "FDTD study on wave propagation in layered structures with biaxial anisotropic metamaterials ," Progress In Electromagnetics Research, Vol. 81, 253-265, 2008.
6. Sabri, M. M., J. Rashed-Mohassel, and N. Masoumi, "Application of FDTD-based macromodeling for signal integrity analysis in practical PCBs," Progress In Electromagnetics Research Letters, Vol. 5, 45-55, 2008.
7. Khajehpour, A. and S. A. Mirtaheri, "Analysis of pyramid EM wave absorber by FDTD method and comparing with capacitance and homogenization methods ," Progress In Electromagnetics Research Letters, Vol. 3, 123-131, 2008.
8. Yegin, K. and A. Q. Martin, "On the design of broad-band loaded wire antennas using the simplified real frequency technique and a genetic algorithm," IEEE Trans. Antennas Propag., Vol. 51, 220-228, Feb. 2003.
9. Sui, W., D. A. Christensen, and C. H. Durney, "Extending the two-dimensional FDTD method to hybrid electromagnetic system with active and passive lumped elements," IEEE Trans. Microwave Theory Tech., Vol. 40, 724-730, Apr. 1992.
10. Pereda, J. A., F. Alimenti, P. Mezzanotte, L. Roselli, and R. Sorrentino, "A new algorithm for the incorporation of arbitrary linear lumped networks into FDTD simulators," IEEE Trans. Microwave Theory Tech., Vol. 47, 943-949, Jun. 1999.
11. Wu, T.-L., S.-T. Chen, and Y.-S. Huang, "A novel approach for the incorporation of arbitrary linear lumped network into FDTD method ," IEEE Microwave and Wireless Components Letters, Vol. 14, 74-76, 2004.
12. Kuo, C.-N., B. Houshmand, and T. Itoh, "Full-wave analysis of package microwave circuits with active and nonlinear devices: An FDTD approach," IEEE Trans. Microwave Theory Tech., Vol. 45, 819-826, May 1997.
13. Shao, Z. H. and M. Fujise, "An improved FDTD formulation for general linear lumped microwave circuits based on matrix theory," IEEE Microw. Theory Tech., Vol. 53, 2261-2266, July 2005.
14. Su, D. Y., D.-M. Fu, and Z.-H. Chen, "Numerical modeling of active devices characterized by measured S-parameters in FDTD," Progress In Electromagnetics Research, Vol. 80, 381-382, 2008.
15. Koh, B. P., I. J. Graddock, P. Urwin-Wright, and C. J. Railton, "FDTD analysis of varactor-tuned patch antenna including device packaging effects ," IEE Electronics Letters, Vol. 37, 1494-1495, Dec. 2001.
16. Sui, W., "Time-domain Computer Analysis of the Nonlinear Hybrid Systems ," CRC Press, New York, 2002.
17. Li, J., L. Guo, and H. Zeng, "FDTD investigation on bistatic scattering from a target above two-layered rough surfaces using UPML absorbing condition," Progress In Electromagnetics Research, Vol. 88, 197-211, 2008.
18. Nogi, S., J. Lin, and T. Itoh, "Mode analysis and stabilization of a spatial power combining array with strongly coupled oscillators ," IEEE Trans. Microwave Theory Tech., Vol. 41, 819-826, Oct. 199.
19. Thomas, V. A., K.-M. Ling, M. E. Jones, B. Toland, J. Lin, and T. Itoh, "FDTD analysis of an active antenna," IEEE Microwave and Guided Wave Letters, Vol. 4, 296-298, Sep. 1993.
20. Emili, G., F. Alimenti, P. Mezzanotte, L. Roselli, and R. Sorrentino, "Rigorous modeling of packaged Schottky diodes by the nonlinear lumped network (NL2N)-FDTD approach ," IEEE Trans. Microwave Theory Tech., Vol. 48, 2277-2282, Jan. 2000.
21. Ei Mrabet, O. and M. Essaaidi, "An e±cient algorithm for the global modeling of RF and microwave circuits using a reduced nonlinear lumped network (RNL2N)-FDTD approach," IEEE Microwave and Wireless Components Letters, Vol. 14, 86-88, Feb. 2004.
22. Vahabi Sani, N., A. Mohammadi, A. Abdipour, and F. M. Ghannouchi, "Analysis of multiport receivers using FDTD technique," Journal of Electromagnetic Waves and Applications, Vol. 23, No. 5-6, 635-643, 2008.
23. Liu, H. and H. W. Yang, "FDTD analysis of magnetized ferrite sphere," Journal of Electromagnetic Waves and Applications, Vol. 22, No. 17-18, 2399-2406, 2008.