If the signal is delayed in time by the dish, then there will be no phase coherency, and it is the phase coherent properties of a parababoid that make it the most commonly used type of reflector for microwave signals.
A direct analogy between optical signals propogating in a fiber and RF signals propogating in free space is not possible - the best analogy would be to compare light in a fibre with RF in a circular waveguide - which somwehat limits the applications of orbital angular momentum for RF/microwave systems. regards Grant > > From: Michael Baker <mp...@clanbaker.org> > To: time-nuts@febo.com > Subject: Re: [time-nuts] Orbital time-delayed angular momentum > phasing....???!! > Message-ID: <5008c114.2090...@clanbaker.org> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Time-nutters-- > > Didier Juges asked: > > What does that do to the focussing properties > > of the dish? > ------------------------ > > I have seen several descriptions of how the dish > needs to be shaped in order to develop the orbital > time-delayed angular momentum signal and still > achieve an integral focus point. I am not sure that > I can describe it, but as I understand it, the dish > is not just split and bent into a cork-screw, but that > the surface of the dish is also continuously shaped so > as to provide a good focus.... It is just that the > signal striking parts of the dish which are increasingly > displaced along the axis of the bore-sight are time > delayed more or less with respect to other surfaces > of the dish. The only way I can see for this to work is > for the dish surface to deviate from a true parabolic > shape incrementally as each particular area is displaced > closer or further away from the focal point. It is a > little hard to visualize and a lot harder to find the > right words to adequately describe! > > 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.