1.2GHz helix antenna design help needed

hi
i want to build a 1.2GHz helix antenna with 50 ohm radiation resistance.
any one have an practical idea?
thanks

If it is just what you have written, you can see the design in "Antennas" by Kraus.for specific designs, some more inputs are needed.What is the type of pattern you want?Omni/Directional?WHat bandwidth, etc.

There are several build descriptions available for 2.4 GHz WAN helix antennas. You just have to rescale from 2.4 to 1.2 GHz. Example:

2.4 GHz: http://helix.remco.tk/

2.4 GHz: http://www3.sympatico.ca/b.zauhar/13cmHelx/13cmHelx.htm