Oh...in your first post you said "Different numbers of wavelengths can be chopped out of the baloney and joined up as a ring." I took that to mean different wavelengths, but you meant different multiples of the same wavelength?
On Mon, May 22, 2017 at 10:05 AM, Chuck McCown <[email protected]> wrote: > Same frequency. Different streams of information launched into the ether > all on the same frequency. > But the streams are oriented in space in a way they do not interfere with > each other. > > *From:* Cameron Crum > *Sent:* Monday, May 22, 2017 9:03 AM > *To:* [email protected] > *Subject:* Re: [AFMUG] OAM > > 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. >> > >
