how does reduced ground plane works?

i am working on a wideband antenna , i have searched some papers and i found that reduce the size of the ground plane is useful to make a wideband. but how does it work?
are there any theory to support the effect?
thanks very much~

You want to google "electrically small antennas" and "radiation resistance" to find some basic papers explaining this stuff.

There is always a tradeoff between getting the size ground plane you desire into the package space you actually have!

i dont know which papers should i use to explain the effect, are there any reference web sites for it?
thx~

plz help~

you can start with this:

The radiation impedance of a wire antenna