HFSS Simulation for WIMAX Dual Band Microstrip Antenna

hi every body
during my thesis
i did my simulation for wimax dualband microstrip antenna with hfss... and i get my goals 2.5 and 5 ghz
but the problem appears during fabrication
where other bands appears and the desired band dont appear
for example i get 1.7 3.4 and 5.15ghz
plz tell me the problem.

There can be several different possible causes, e.g.:
- the constructed model differs from the simulated one
- the simulation has errors greater than expected
You should provide more information.
Regards

Z

thanks zorro for ur reply
here i will attach my design and its fabrication

in your fabricated model the substrate and ground plane dimensions are not same. by my experience it does make difference.

what you can do is that in your simulation model you can make your substrate and ground plane dimensions same as that of fabricated one and see if it changes your simulated results or not.

good luck :)

thanks alot rabiazainab i do what you said ...it is really effect the results.
but when i change airbox size new results appears...