Amateur makes the point of paraboloid antenna---The relation of the radiation deflection Q of the F/D of paraboloid antenna and source of make a present of
F/D (the focus that F is parabola, the caliber that D is parabola) the deflection Q with source of make a present of is appurtenant relation, the diameter of the paraboloid antenna that ability decides to you want to make after the deflection that has cause of make a present of only that is to say is affirmatory reachs focal length. Know F/D=0.3 only as an amateur- - 0.5 it is insufficient, how can just make the form a complete set of an antenna and source of make a present of uses appropriate F/D namely, this problem is very serious, the efficiency that it affects aerial system directly and letter a confusion of voices are compared etc. It is place of source of make a present of is inherent that graph 1-1 place shows Q, source of make a present of decided, q also decided.
The antenna that make should decide source of make a present of above all, only the deflection of source of make a present of is foregone, ability makes the antenna of different diameter by different F/D, and source of make a present of just is made after should not making antenna good, because come so the effect of very inaccessible ideal, sure generation is like the circumstance of graph 1-2 or graph 1-3. The circumstance of graph 1-2 can make ground catoptric clutter enters source of make a present of, and the microwave of aerial brim and diffraction wave also can enter source of make a present of, make the letter a confusion of voices that aerial receives a system is compared reduce. The circumstance of graph 1-3 can make the utilization rate of aerial reduces the waste that creates a person to be and of signal by valve also entered source of make a present of at the same time. The relation of F/D and Q is: F/D=1/4*Ctg Q/2.
The antenna that so first deflection of source of make a present of makes how many diameter according to you want again decides F=D* after that (1/4*Ctg Q/2) , next according to parabola equation: X=Y*Y/4F scale gives a model.
The caliber of parabola antenna can use next form calculation:

| The deflection of source of make a present of (Q) |
100 degrees |
120 degrees |
160 degrees |
180 degrees |
| The efficiency of aerial (K) |
70% |
60% |
55% |
50% |
General amount to half brace up child source of make a present of (the reflector after the belt) the deflection with source of helix make a present of is 100 degrees or so.
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