modification in desin of antenna 4 dual band operation..

i design antenna at 1800 mhz & by proper feed postion i got dual band operation @ 1700 & 1400 but i want lower band @900 mhz so if any one know d modification or suggestion in d given model i uploadin d file...

Enlarge the profile of your model, especially the short side of your patch, then you can get an antenna working at lower freq.

But the dual band might not be their when you enlarge it.

So, if you still need the dual band, mybe you can open some slots on your patch.

k..i wud enlarge my shorte side i also put sme slot on it...