Agilent 5990-3225EN State of the Art in EM Software for Microwave Engineers - White Paper c20140829 [13] free download

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Keysight Technologies State of the Art in EM Software for Microwave Engineers White Paper Introduction The growing number and complexity of high frequency systems is leading to an increased need for electromagnetic (EM) simulation to accurately model larger portions of the system. There are several different technical approaches to EM simulation, and while no method is generally superior to the others, each one of them is aligned with one or more application areas. This article will discuss the three most established EM simulation technologies: Method-of-moments (MoM), inite element meth- od (FEM) and inite difference time domain (FDTD), linking the simulation technology to solving speciic applications. Authors: Jan Van Hese, Keysight Technologies Jeannick Sercu, Keysight Technologies Davy Pissoort, Keysight Technologies Hee-Soo Lee, Keysight Technologies 03 | Keysight | State of the Art in EM Software for Microwave Engineers - White Paper The method Overview of the method-of-moments of moments Among all techniques to solve EM problems, the method of moments (MoM) is one of the hardest to implement because it involves careful evaluation of Green's functions and EM coupling integrals. Maxwell's equations are transformed into integral equations which upon discretization yield the coupling matrix equation of the structure. The advantage of this transform is that the current distributions on the metal surfaces emerge as the core unknowns. This is in contrast to other techniques which typically have the electric and/or magnetic fields (present everywhere in the solution space) as the core unknowns. Only the surfaces of the metals, where the currents flow, need to be taken into account in the meshing (Figure 1). Hence the number of unknowns (or the size of the matrix) is much smaller. This results in a very efficient simulation technique, able to handle very complex structures. This benefit comes with a price as the integral equations are not applicable