Need help with wideband dipole array with 4:1 ratio

Hi to all,
I have a class project about "wideband dipole array" of ratio 4:1.
I'll be happy if anyone help me!
thanks.

I assume you are after a 4:1 frequency range. You will have two big challenges to deal with, finding an element with enough bandwidth and element spacing in the array at the band edges.

Good luck.