Aperture coupled p@tch antenna design

Hi all,
Has anyone designed ( approximately ) an aperture coupled p@tch antenna ? I basically want to know how do you obtain a first estimate of the slot dimensions and the stub length for maximising the bandwidth. Any references to papers or book chapters in this regard will be most welcome. Thanks for the time.

-svarun

the stub length should be less than λeff/4.

try these papers:
http://www.ecs.umass.edu/ece/pozar/aperture.pdf

"Guidelines for design of electromagnetically coupled microstrip patch antennas on two-layer substrates"
By: Georg Splitt and Marata Davidovitz
IEEE transactions on antennas and propagation, VOL 38, No. 7, July 1990

Regards,
Hassan