What does that do to the focussing properties of the dish? Didier KO4BB
Michael Baker <mp...@clanbaker.org> wrote: >Timenutters-- > >Along the lines of splitting time into small increments, there >is an interesting article in the May 2012 issue of the >IEEE Spectrum Journal. > >It describes experiments with what I am calling "cork-screw >time-shift phasing modulation" or "orbital time-delayed angular >momentum phasing" for lack of a better description of the >process. This is not the same as circular-polarization of a >radiated signal. > >Visualize a 4-ft dia parabolic reflector which has been cut >(sliced) in a straight line from any arbitrary point on its outer >edge to its center. Then, at the outer lip of the reflector >surface, pull one side of the cut about a foot forward of the >other side of the cut. The separation is greatest at the edge >of the dish, gradually becoming less and less as the cut >approaches the center of the dish. > >The concept is that RF energy from the feed progressively >strikes different areas of the dish slightly ahead (time-wise) >from RF energy that strikes other parts of the dish. Because >the surface of the dish resembles a cork-screw the signal >from the dish has elements that are time-delayed with >respect to other parts. Accordingly, data elements can be >incorporated into the signal which have sightly different >time-delay angular momentum properties. Again, the folks >working on this insist that this is not the same as circular >polarity of the radiated signal such as is obtained with a >helix antenna. > >At the receive end, the process is reversed, producing a >signal which when demodulated can contain extra levels >of data modulation superimposed on it. > >The article points out that there are skeptics of the process >who say that this same modulation procedure can be done >with other methods although the modulation and demodulation >process would be much more complex. > >The orbital angular momentum of photons in the optical >realm has been extensively studied, although applying these >principles to RF is something new. > >Mike Baker >------------------------------ > > > > >_______________________________________________ >time-nuts mailing list -- time-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. -- Sent from my Motorola Droid Razr phone with K-9 Mail. Please excuse my brevity. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.