fractal antenna
hi everybody,
i have a problem concerning the conception of a fractal antenna with koch geometrie.I sucess to make an antena with 2 iteration whitch resonnant frequencie is 915 Mhz however the antenna must be contained in a rectangle of 50*80 mm(milimeter) so I reduced the superficie of the antenna by keeping the same size of wire until to obtain the right dimensions.But when I simule I find an S11 between -5 and -6dB whereas it should be inferior to -10 dB.I don't know how to decrease the S11.
I NEED HELP.
Thanks.