Signals from satellites are rather weak, so they require what is called a dish antenna. It has a particular shape and made of metal. The shape is probably the biggest issue.. It is called parabolic. A radio signal from space arrives at the dish in a parallel beam, When it strikes the dish it bounces back, but due to the parabolic shape it bounces from each point on the dish to a single point out in from of it, called a focus. It would probably not be worth the effort.

In any case, if you google something like "diy sat tv antenna" you will get the regular 75000 pages listed. :You can go from there.

Dear v1sor , thank you very much for your reply ...i'm rather informed about SAT TV dish principle and i know the average dish gain to be achieved for good signal is some about 39 dB, i heard : for the dielectric hemisphere antenna (....may be home made -i don't know) it is quite possible to obtain this gain.... it depends on design , materials dielectric constant used and their loss...what do you think about?

I found a website about a company in Japan that is making the lens for the antenna that you want to build. I too am interested in this type of antenna for HDTV reception, what do you think? Here is the website http://www.sumitomoelectricusa.com/scripts/products/luneQ/luneberg.cfm

Dear mglatfelterjr ,thank you for this site, good, but wht do you think about this antenna to be homemade , is it possible? If yes which way, materials (foam? what type?), constructions? ets...???

I believe it can be made, maybe dielectric foam, you need some type of reflector and a way to mount the LNB. I will talk to my uncle, he likes to invent things.

...there is the deep theory in Luneberg antenna...in some sources they said the three or five layers are enough for appropriate focusing but the problems in materials of different dielectric constant and construction principles...also must be good sute to rugged environmental conditions for this sample ....etc.