dish material
Can anyone suggest me, the best material for the dish ?
It depends upon the frequency. The basic structure can be anything like wood or fiberglass. The reflective surface can be continuous metal for short wavelengths and woven wire for longer ones.
One classic lower frequency method is to make ribs out of wood and put the woven wire on the ribs. By woven wire I mean things like "chicken fence" material or "window screen" material.
For solid dish (KU-BAND) which 'metal' material is the best ?
If you are building this at home, copper foil with sticky backing should work well.
We use a mold to get a carbon fibre dish that is subsequently painted with an 8um conductive paint. This is for Ku band.
Cassegrain system with corrugated feed horn.
We have 0.1mm tolerance across the whole dish. This is necessary for uplink SLL suppression.
/kazam
What should be the best material when frequency is 2.4 Ghz.
In ANY parabolic antenna, you are making a GOOD REFLECTOR. So the material should be as conductive as possible. Good antennas are made as aluminum molds or pressed of aluminum sheet to a precise shape.
Many people try to make molds of laminates; then covering the surface becomes a problem. The best is to use copper-foil stickers as described above. Aluminum stickers if used, need to overlap by 0.1" or 3 mm for good results. Conductive paints are often difficult and do not survive long time. Beware- aluminum paints often consists of small particles immersed in a glue- this does not work well as the particles cannot connect with each other, and such antenna will not focus!