What ANTENNA do you recommend?

I want to design an simple antenna at 16 GHz on PCB (x-y plane). I want it to be directional in the 0z
Thank you!

Your requirement is really too general. There could be additional constraints that you need to look at gain, bandwidth, return loss, polarization, ... ?

But to start you off, I suggest you take a look at patch antennas. They should be simple enough to realise and also directional.

http://www.emtalk.com/tut_1.htm

thank you for your reply .
I am sorry about my big negligence.
Actually " I want to design an simple antenna at 16 GHz on PCB (x-y plane). I want it to be directional in the 0y", not in the 0z :(
At the beginning, i use tapered slot antenna but it is not simple enough.
I hope you could recommend me another antenna, so that i could combine it with my old antenna .
Thank you very much!

I cannot think of any planar/PCB type antennas which might have radiation directed in the plane containing them.

Your best bet might be to go with the slot antennas (like a vivaldi antenna, .hfss model attached). These are generally like slotted waveguide antennas and not strictly planar.

Thank you for your help Jeeudr!