Apart from their shape what is the diffrence between a parabolic & a elliptical dish in terms of performance?

Answer 1

The elliptical dish narrows the beamwidth along its major axis. This enables better adjacent satellite discrmination over the parabolic reflector when the eliptical dish is aligned properly with satellite arc. In terms of the RF link analysis this provides a higher C/I figure and thus a better overall C/N, which relates directly to signal quality and availability.

Answer 2

An ellipse has two focii, a parabola has only one. By an elliptical dish, I'm assuming that you mean a part ellipse (say a half). Now light (or radio waves) approach the dish as parallel rays (to use a simplistic term) The power of the dish will depend upon how many of these "rays" are focussed upon the focus point. As the dish grows larger, the focussing error will become greater if the shape is elliptical. On the other hand, a parabola, by its very definition, will focus approaching parallel rays to its focus, irrespective of how large the dish is. Thus, if the diameter is small, then there is little to choose between the two shapes, but as the dish diameter increases, then the parabolic shape will perform better than the elliptical.

Answer 3

One half of an ellipse is a type of parabola ...but as far as the question goes performance of the dish is purely relative to the required focal point.....So i Guess the focal point distance is the characteristic most evaluated . If you want extreme foci then open the parabola and inversely close to shorten the foci. Perhaps i should explain the construction of an ellipse a little better though...if one was to consider a round tube circle sawed in half at any angle an ellipse would be formed. In a true parabola the legs extend to tangency but do not ever curve inward again.....Well good luck On this ....from the E.