Bandwidth enhancement

I am doing my final year UG project in antenna domain. My goal is to design an coaxial feed patch antenna of high gain, isotropic radiation pattern and large bandwidth. I have got high gain and radiation pattern but i do not know how to increase bandwidth. How do i increase bandwidth without affecting other parameters?

Bandwidth and gain are some sort of inversely proportional to each other... there is always a trade of b/w them.. keeping them both up is practically a very difficult task...!

ok, tell me the way to increase the bandwidth.

I think work more on your input matching.. how is your S11 response? It is prefered to have it below -10db over your entire band.

There are numerous techniques described in the literature. What have you considered thus far? What are your objectives and what have you accomplished?

One easy way to increase the bandwidth is to design for higher and higher frequency. A 10 percent bandwidth at 1 GHz is not as wide as the same 10 percent bandwidth at 10 GHz center frequency. In many cases this is what is driving systems to higher and higher frequencies.