design of antenna

Hi
I am interesting in design of log periodic antenna operating in HF ,VHF ,
and UHF bands
Can any one tell how to design, to implement my own antenna?
Hwo to get the required software?

keep in mind that 3-1frequencies ratios are easy and 10-1 frequency ratios are difficult. The usual thing is to stack the antennas on the same mast, each one covering part of the frequency range.

The famous antenna handbook by Jasik would be the place to start.