In this paper, we present an efficient hybrid spatial-spectral formulation of the method of moment (MoM) in conjunction with the Mixed-Potential Integral Equation (MPIE) for planar circuit analysis. This method is based on the decomposition of the Green's functions in two parts: quasi-static in the near field region and the dynamic contribution in the far field region. Using this decomposition of Green's functions, the method of moment matrix entries can be reduced and expressed to a sum of two integrals. The first one is expressed in the spatial field and corresponds to the quasi-static contribution. It is analytically evaluated after a development in Taylor series of the exponential terms in the function to integrate. The integrals expressed in the spectral field and corresponds to the dynamic part have the advantage of being calculated on a finite range and this independently of the choice of the basis and test functions. The integrals expressed in the spectral field are performed by using numerical integration. It is also demonstrated that this hybrid method has accelerated the matrix fill in time by using a Fast Fourier Transform (FFT) algorithm. In order to validate the proposed method, numerical results are presented.
2. Uwaro, T. and T. Itoh, "Spectral domain approach," Numerical Techniques for Microwave Millimeter-Wave Passive Structures, 334-380, John Wiley & Sons, Inc., 1989.
3. Emre, M., M. I. Aksun, and G. Dural, "Critical study of problems in discrete complex image method," IEEE EMC Symposium, Conference Proceedings Istanbul, Turkey, May 11--16, 2003.
4. Aksun, M. I. and G. Dural, "Clarification of issues on the closed form Green’s functions in stratified media," IEEE Antennas and Propagation Magazine, Vol. 53, 3644-3652, 2005.
5. Davidson, D. B. and J. T. Aberle, "An introduction to spectral domain method-of-moments formulations," IEEE Antennas and Propagation Magazine, Vol. 46, No. 3, 251-259, 2004.
doi:10.1109/MAP.2004.1374083
6. Mariottini, F., A. Cucini, and S. Maci, "A hybrid spectral/spatial method to evaluate the active Green’s function of large planar rectangular arrays: A combined asymptotic/numerical algorithm," IEEE Transactions on Antennas and propagation., Vol. 54, No. 3, 878-887, 2006.
doi:10.1109/TAP.2006.869903
7. Alatan, L., M. I. Aksun, K. Mahadevan, and M. T. Birand, "Analytical evaluation of the MoM matrix elements," IEEE Trans. Microwave Theory Tech., Vol. 44, No. 9, 1996.
8. Samet, A. and A. Bouallegue, "Fast and rigourous calculation method for MoM matrix elements in planar microstrip structures," Electronics letters., Vol. 36, No. 9, 2000.
doi:10.1049/el:20000626
9. Essid, C., M. B. Ben Salah, A. Samet, and A. Kouki, "An efficient space domain formulation of the MoM method for planar circuits," PIERS Proceedings, 722-724, Cambridge, USA, July 2--6, 2008.
10. Chow, Y. L., Y. G. Yang, D. G. Fang, and G. E. Howard, "A closed-form spatial Green’s function for the thick microstrip substrate," IEEE Trans. Microwave Theory Tech., Vol. 39, No. 3, 588-592, 1991.
doi:10.1109/22.75309
11. Aksun, M. I., "A robust approach for the derivation of closedform Green’s functions," IEEE Trans. Microwave Theory Tech., Vol. 44, No. 5, 651-658, 1996.
doi:10.1109/22.493917
12. Kipp, R. and C. H. Chan, "Complex image method for sources in bounded regions of multilayer structures," IEEE Trans. Microwave Theory Tech., Vol. 42, No. 5, 860-865, 1994.
doi:10.1109/22.293536
13. Aksun, M. I., F. Caliskan, and L. Gurel, "An efficient method for electromagnetic characterization of 2-D geometries in stratified media," IEEE Trans. Microwave Theory Tech., Vol. 50, No. 2, 1264-1274, 2002.
doi:10.1109/22.999138
14. Park, S. O., C. A. Balanis, and C. R. Birtcher, "Analytical evaluation of the asymptotic impedance matrix of a grounded dielectric slab with roof-top functions," IEEE Trans. Microwave Theory Tech., Vol. 46, No. 2, 251-259, 1998.
15. Chae, C. B., J. P. Lee, and S. O. Park, "Analytical asymptotic extraction technique for the analysis of bend discontinuity," Progress In Electromagnetics Research, Vol. 33, 219-235, 2001.
doi:10.2528/PIER01012102