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I am an electronics noob and searched around the FAQ and this question seems askable. My questions are:

  1. How can I create polarized signals and are there any parts I need to be aware of to easily do so? (not receive and filter out polarized signals but send them)

  2. Do I need a different oscillator for each type of polarized signal I want to send out?

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So I'm not sure what your working on (context helps!), but here's some general advice:

A signal is generally polarized by the orientation of the antenna you are outputting from. A vertically oriented antenna will output waves which will be more easily picked up by another vertically oriented antenna. A horizontally oriented antenna will output waves which will be more easily picked up by a horizontally oriented antenna.

Vertical polarization has the benefit of being omni-directional (when using a whip or dipole antenna). Horizontal polarization has the benefit of bouncing off the surface of the earth (or ocean) with less loss, thus generally traveling further with the same power. The downside to horizontal polarization is that you generate a directional wave so it needs to be aimed at the target.

You can get a varying polarization by having two antennas orthogonally oriented and then varying the strength of the signal in the antennas.

I hope that helps!

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  • \$\begingroup\$ Great answer but what about polarization other than horizontal and vertical ( as defined in nrcan.gc.ca/earth-sciences/geography-boundary/remote-sensing/…). Context is a paper i am trying to work on. \$\endgroup\$ – qwrty Oct 28 '12 at 8:42
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    \$\begingroup\$ all polarisation types can be broken down into orthogonal (e.g. horizontal and vertical) components. \$\endgroup\$ – geometrikal Oct 28 '12 at 10:32
  • \$\begingroup\$ To be complete, the breakdown into components must be considered to be a function of time - as circular polarizations are also a possibility. These can be produced by introducing a phase delay between the orthogonal emitters, using a helical emitter, etc. \$\endgroup\$ – Chris Stratton Oct 29 '12 at 4:43
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It's the orientation of the antenna that polarises the signal. Not the preceding circuitry.

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  • \$\begingroup\$ Sorry cant upvote \$\endgroup\$ – qwrty Oct 28 '12 at 8:42
  • \$\begingroup\$ Yes, except for the possibility of inversion - which only matters if there is some common sense of time for a phasing reference. \$\endgroup\$ – Chris Stratton Oct 29 '12 at 4:39

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