Discussion Forum

Posted: 7 years ago 17 feb 2018, 14:33 GMT-5

Updated: 7 years ago 17 feb 2018, 14:42 GMT-5

Are you seeking to model an electromagnetic (vector) wave or some other kind of wave (such as a generic scalar wave)? Bear in mind that in 3D, there are no true spherically-symmetric EM waves, except for things like random statistical/thermal sources (for which RF/microwave and wave optics would not be appropriate tools anyway) . Yet, you say "spherical" and "incident" wave. If your interest concerns an EM wave, then what kind of symmetry, polarization, and pattern of radiation do you actually want? (Again, you can't have complete spherical symmetry in an RF wave, since it doesn't exist, i.e., it is not a solution of Maxwell's equations.) Did you also really want to model the port as a receiver, and have the wave incident upon it? It is often easier to model ports as sources, and for many circumstances, reciprocity holds and you can learn the same things from such a model... Are you, perhaps, trying to model an antenna? If so, you should be more interested in understanding and managing the connection from your port (on a transmission line or waveguide) to the antenna, rather than thinking as if the port itself were launching (or receiving) the subject radiated wave. (Your port can in some cases be on the antenna itself, but in that case, you should probably still think of the port as being connected to a zero length transmission line, the latter which then connects to the antenna) After all, the antenna will couple to radiated waves (whether as a receiver or transmitter) per the calculations done by the FE code; you just need to add the appropriate external boundary conditions (bcs) or incident wave conditions. For radiating sources, you can use scattering bcs or perfectly matched bcs on exterior boundaries. For receiving, you should consider using the wave-scattering formalism (often used in radar cross-section work). So, anyway: (1) you might want to explain here much more about what you are actually trying to do, and (2) you might want to post a model of what you have done so far, so that others here can offer more useful and relevant advice. Good luck.