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All of the circularly polarized phased arrays that I can find use elements that are themselves circularly polarized, that is, two perpendicular dipoles that are crossed at their midpoints (the picture on the left). Would something like the pattern on the right work, where the antennas are still perpendicular but offset? If so, would the horizontal and vertical elements still be fed 90 degrees out of phase, or would it get more complicated? I can imagine that this would make them easier to pack, but it's very possible that I've missed something obvious.

Thank you so much!

Two different patterns for arranging dipole antenna elements

user201537
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In theory you could, as in the far field both of these antennas will produce waves that seem to originate from approximately the same point. So from an observer in the far field, that is looking perpendicular to the surface of the antennas, these can product circular polarization.

However, I think it will actually be harder to make, since in the case of crossed dipole, you gain from the fact that the fields of one antenna are zero along the symmetry axis. Here is an image to illustrate (simplified but should get the concept across). Vertical antenna has an illustration of it's fields shown.

fields of different structures

The nature of the crossed dipoles means that the differential mode (which is the mode dipoles work on) of both antennas is naturally isolated from the other. When you put them next to each other, this is not the case.

Joren Vaes
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