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how can I set some incoherent point sources in 3D in RF modeling

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it seems all the point source array I set using conventional methods is coherent, does that have any way to figure out this problem?

1 Reply Last Post 6 gen 2010, 14:07 GMT-5
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Robert Koslover Certified Consultant

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Posted: 1 decade ago 6 gen 2010, 14:07 GMT-5
I'm surprised no one responded to this question earlier. RF problems are normally solved as either frequency-domain or time-domain wave-type solutions to Maxwell's equations. All frequency-domain problems are "coherent" at any given frequency, essentially by definition. However, multiple incoherent sources could in principle be modeled in time domain using source driving functions that are nearly random (but kept within some finite frequency bandwidth). However, a better solution to your class of problem would likely be to apply a different method entirely. For example, incoherent optical behavior is for many purposes nicely described by ray-tracing/geometric optics. Finite elements (on which Comsol Multiphysics is based) is apparently not the best way to implement that. Fortunately, there exist many low-cost, and some free, ray-tracing codes available for downloading on the internet. Just do a search for ray-tracing codes. Good luck.
I'm surprised no one responded to this question earlier. RF problems are normally solved as either frequency-domain or time-domain wave-type solutions to Maxwell's equations. All frequency-domain problems are "coherent" at any given frequency, essentially by definition. However, multiple incoherent sources could in principle be modeled in time domain using source driving functions that are nearly random (but kept within some finite frequency bandwidth). However, a better solution to your class of problem would likely be to apply a different method entirely. For example, incoherent optical behavior is for many purposes nicely described by ray-tracing/geometric optics. Finite elements (on which Comsol Multiphysics is based) is apparently not the best way to implement that. Fortunately, there exist many low-cost, and some free, ray-tracing codes available for downloading on the internet. Just do a search for ray-tracing codes. Good luck.

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