In this work we present a new physics-based approach for formulating MoM problems based on the use of dipole moments (DMs) --- as opposed to the conventional Green's functions. The proposed technique is valid over the entire frequency range without any need for special treatments and is also free of singularities associated with the Green's function. The DM approach can be used equally well to both PEC and Dielectric objects. We also introduce certain refinements to the DM method to improve its computational efficiency like the use of higher-order basis functions, combining the DM with the Characteristic Basis Function Method (CBFM), the use of closed-form expressions for the calculation of interaction matrix elements and employing Fast Matrix Generation (FMG) for electrically large problems. We also demonstrate ways to incorporate lumped loads, capture sharp resonances even at low frequencies, calculate the input impedance of small antennas, calculate fields from irregular geometries; from faceted surfaces; from geometries with slot and slit; and also demonstrate the capability to model microstrip line type of geometries with fine features.
2. Harrington, R. F., Field Computation by Moment Methods, The Macmillan Company, New York, 1968.
3. Mittra, R., Computer Techniques for Electromagnetics, Hemisphere Publishing Corporation, New York, 1987.
4. Harrington, R., Time-harmonic Electromagnetic Fields, IEEE Press, New Jersey, 2001.
5. Bringuier, J., "Multi-scale techniques in computational electromagnetics,", Ph.D. Dissertation, The Pennsylvania State University, 2010.
6., "Numerical electromagnics code,", [Online], available: http://www.nec2.org/.
7. Panayappan, K., "Novel frequency domain techniques and advances in finite difference time domain method (FDTD) for efficient solution of multiscale electromagnetic problems,", Ph.D. Dissertation, The Pennsylvania State University, 2013.
8. Mittra, R., Computational Electromagnetics: Recent Advances and Engineering Applications, Springer-Verlag, New York, USA, 2013.
9. Rao, S., D. Wilton, and A. Glisson, "Electromagnetic scattering by surfaces of arbitrary shape," IEEE Transactions on Antennas and Propagation, Vol. 30, No. 3, 409-418, 1982.
10. Lucente, E., A. Monorchio, and R. Mittra, "An iteration-free MoM approach based on excitation independent characteristic basis functions for solving large multiscale electromagnetic scattering problems," IEEE Transactions on Antennas and Propagation, Vol. 56, 999-1007, April 2008.
11. Mittra, R. and K. Du, "Characteristic basis function method for iteration-free solution of large method of moments problems," Progress In Electromagnetics Research B, Vol. 6, 307-336, 2008.
12. Mehta, N., "Numerical analysis of frequency selective surfaces,", Master’s Thesis, The Pennsylvania State University, 2010.
13. Kwon, S. J. and R. Mittra, "Impedance matrix generation by using fast matrix generation (FMG) technique," Microwave and Optical Technology Letters, Vol. 51, 204-213, January 2009.
14. Jordan, E. and K. Balmain, Electromagnetic Waves and Radiating Systems, Prentice-Hall Series in Electrical Engineering, Prentice-Hall, 1968.