Help me choose suitable printed antenna type and software for it

HI Everybody

actually , i'm in the way of designing a printed antenna for a short range
communication in free space so that the are not such restrictions that
wlan antenna's have inside buildings.
as you better know yourself , there are variety of types of printed
antenna's such as patch's (rectangular,circular,triangular,...) , dipoles,
travelling wave ones & slot antennas and array's of all of them .

well this huge amount of options for design really confuses me..!
i would be so happy if u help me to
choose the best way.

ive got tutorial's for both softwares ADS & HFSS i would be happy too if
you suggest me the best one for this particular design.

after all my antenna requirements are the following :

FREQ RANGE : 2400- 2500 MHZ
Efficiency : > 50%
Peak Gain : > 0 dbi
VSWR : < 2:1
Polarization : linear
Weight : 0.1 gr
Temperature : -40 - 85 C
Impedance : 50 ohms

very very very thanks to your patience and attention

I think that a simple pαtch antenna should do the job (rectangular) like the one given in HFSS example. What are the constraints with respect to size ? Then you should be looking at using shorting pins/capacitive loading etc.

-svarun