Better antenna diversity
Better antenna diversity
(OP)
If I had limited package size, and wanted two antennas for some spatial antenna diversity, which option would be better: Option A or B?
I assumed Option A, but then I realized I was not sure.
I assumed Option A, but then I realized I was not sure.
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RE: Better antenna diversity
Another observation. Since the two monopoles are aligned the same (collinear) there's no polarization diversity. Depending on your application, it might be better to have them at an angle.
RE: Better antenna diversity
But VE1BLL point on the polarization is a much more important issue for good diversity. You need to rotate one of the antennas by 90 degrees, or maybe both by 45 degrees so they are more orthogonal to each other. Due to path interference from objects and reflections off surfaces, or the ground, the polarization of the signal may be change.
RE: Better antenna diversity
RE: Better antenna diversity
It is good that someone else agrees with Option A being "farther apart", although since this is all withing one wavelength...not sure what that actually means. As far as coupling of one antenna to the other, I will build two and see what the proximity effect is.
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Maguffin Microwave wireless design consulting
RE: Better antenna diversity
(The next big thing in multi-antenna systems is MIMO.)
RE: Better antenna diversity
As far as spacing...I will go with the most my package will allow, which looks like around 3/4 wavelength between feed points.
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Maguffin Microwave wireless design consulting
RE: Better antenna diversity
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RE: Better antenna diversity
But even in the worst case, it's not going to be *that* much higher than -18 dB. Most of the RF has to go in other directions...
RE: Better antenna diversity
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Maguffin Microwave wireless design consulting
RE: Better antenna diversity
Hence, say the ground plane is vertical, even rotating a chip antenna 90 degrees to horizontal (with the ground plane still vertical) will still have most radiation being Vertical polarization.
Wider spaced is preferred, current on ground plane is more separated.
kch
RE: Better antenna diversity
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Maguffin Microwave wireless design consulting