patch antenna without ground

That is interesting. Do you by any chance still have the paper? Can you forward the paper on to me?

do you mean cutting some slots in the ground plane ?

i found an explanation but i'm not sure it still seems reasonable
rempving a part from the ground (usually till the edge of the patch) decreases εeff
so band width increases

Hi Yahia Muhammad,

I think removing ground plane will increase BW. But by doing the same antenna

directivity will get reduced,because after reflection from the ground plane all waves

will be directed towards Rx. If there is no or small ground plane only few will be

directed remaining things will be losed or otherwise what we'll call us

omnidirectional antenna which'll result in less gain.

We can use Parasitic patches(Parasitic Radiators) for increasing the Bandwidth.

yes balaguru thavamani the resulting antenna was omni directional the radiation pattern is shown in this pic

I think if a patch antenna doesn't have a ground surface, it just like a dipole antenna. So it should have a omnidirectional pattern.

you can read some papers about PBG structure,

In patch antenna ground plane functioned as reflector, i thought u read about DGS where some of ground was defected to improve antena caracteristic like Bw, gain,etc