How do you have different wavelengths and not different frequencies? Or are you referring to frequency as some channel of a certain bandwidth?
On Mon, May 22, 2017 at 9:35 AM, Chuck McCown <[email protected]> wrote: > I finally re-read an IEEE magazine enough times to understand the OAM > propagation. (Orbital angular momentum) > > If you have missed it, for the past 20 years there have been thousands of > white papers written on a type of radio signal called OAM. It looks a lot > like circular polarization but the interesting thing is that you can use > the same frequency for multiple streams that do not interfere. In theory > an infinite number of streams. > > So, here is how I got it explained to myself so that I could understand it. > Using a special antenna, each wave front is launched like a smoke ring. > And the wave itself , or integer multiples of the wave are like little > snippets of string formed into a ring. That is the smoke ring. As you > traverse it around the ring the phase of the smoke changes. So think of it > as taking a n-lambda foot long chunk of the radio signal. Chop it out > like a long piece of baloney and join it to its self. Then set up some > kind of launcher that can throw these rings of signal at the other end, not > like a frisbee but like a pie in the face. > > Different numbers of wavelengths can be chopped out of the baloney and > joined up as a ring. If you have rings from one transmitter made out of > two wavelengths and rings from a different transmitter of three > wavelengths, they can all use the same frequencies and they will not > interfere with each other. > > The downside is you have to have some really complicated funky antennas at > each end and they have to be aimed up perfectly. The antenna center must > be in the center of the smoke ring to receive it properly. If it is off to > the edge it will not have the clean separation from the other rings with > different integer multiples. > > Should work for very high frequencies over short distances. Like 10 GHz > on up. They are doing it with lasers. I have see the 10 GHz antennas. > They look like the internal parts of a rotary snowplow. >
