parallel coupledl band pass filter using HFSS

hi every one i want your help in designing a parallel-coupled band pass filter has the following characteristics
Fc=10 GHZ
B.W=1 GHZ
er=3
hight of substrate =1.5 mm

and that's all what i know about it knowing that this is my first time to design filter using HFSS
thanks

HFSS is an analysis tool. It will analyze the filter if the layout already exists.
If you start from electrical specifications, and do not have a layout yet, HFSS is the wrong tool.
Instead, use a filter synthesis tool ike Nuhertz Filter Solutions (commercial product) or Nuhertz Filter Free (free limited version).

thanks for your respond but all what i need is to know to know the width and the length of filter elements just and the equations to calculate it

We have synthesis tools because it's not that simple ...

You can start from AWR, there are some examples for such filters, you need modify the examples.
And you should know the out band, or stop band specifications for filter design.