wide bandwidth rectangular slotted patch antenna

Hi..can anybody explain, what exactly happens when a rectangular slot is introduced in the patch? in terms of surface current or any other means..how bandwidth is improved when slot is introduced? please help

Thanks :)

Hi,
If I'm not mistaken, the slots will actually produce its own resonance combining with the existing resonance and therefore improves the bandwidth. Probably this is why some slots are designed close to the radiating edges of the patch.
The slots also could be responsible for the excitation of certain TM resonant modes in the patch and therefore will improve the bandwidth when these TM modes are excited. Maybe the links below could help to explain further in details.

http://www.iject.org/vol2issue4/halappa.pdf
Slotted Rectangular Microstrip Antenna for
Bandwidth Enhancement - IEEE Paper
http://www.medwelljournals.com/fullt...omm.2010.54.59

All the best

Thanks for your reply:)