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Far Field for antenna arrays ?
Posted Aug 29, 2018, 6:46 p.m. EDT RF & Microwave Engineering, Wave Optics Version 5.3a 4 Replies
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How to plot the 3-D Far Field for an antenna array? The simulations are carried out using the floquet periodic boundaries just for one antenna element. I'd like to understand the array effect on the far field pattern versus the one for an antenna element.
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Floquet boundary conditions are a way of modeling a single element as if it were part of an infinite array. You are unlikely to be interested in the pattern of a truly infinite array. However, you can compute the pattern contributed by a single element.
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Floquet boundary conditions are a way of modeling a single element as if it were part of an infinite array. You are unlikely to be interested in the pattern of a truly infinite array. However, you can compute the pattern contributed by a single element.
Thanks Robert for your reply. As you mentioned, I'm intersted in the far field pattern of an infinite array. Is there any way to compute this?
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Sorry, but did you mean to say that you are interested in the pattern of a finite array? If so, you can either: (1) model the whole finite array (this is the best and most accurate way, but most computationally intensive), or (2) superimpose analytically (keeping track of amplitude, phase, and vector direction) the computed far-fields from a repeated single element at different locations from your field point(s) of interest, while using the Floquet boundary conditions already noted. However this second approach ignores the fact that the true elements in a finite array do NOT all cleanly behave like elements embedded in an infinite array, due to the many asymmetric couplings among them.
Infinite arrays are simply not the same as finite ones. If you are truly interested in an infinite array, then your problem of interest is probably better posed as a question about wave scattering or of diffraction gratings or of waves interacting with crystal lattices, etc., rather than as one of array antenna analyses, although obviously there are some similarities. Good luck.
-------------------Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
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Sorry, but did you mean to say that you are interested in the pattern of a finite array? If so, you can either: (1) model the whole finite array (this is the best and most accurate way, but most computationally intensive), or (2) superimpose analytically (keeping track of amplitude, phase, and vector direction) the computed far-fields from a repeated single element at different locations from your field point(s) of interest, while using the Floquet boundary conditions already noted. However this second approach ignores the fact that the true elements in a finite array do NOT all cleanly behave like elements embedded in an infinite array, due to the many asymmetric couplings among them.
Infinite arrays are simply not the same as finite ones. If you are truly interested in an infinite array, then your problem of interest is probably better posed as a question about wave scattering or of diffraction gratings or of waves interacting with crystal lattices, etc., rather than as one of array antenna analyses, although obviously there are some similarities. Good luck.
Thanks for your detailed reply.