coplanar waveguide (cpw)

I have a CPW, but I dont understand how to set up the excitation. With a CPS I draw a rectangular surface equal to the cross section of the CPS and I set a lumped port on it, with an integration line that goes from one strip to the other (orthogonally to the parallel faces of the two strips).

Now, with a CPW I cannot draw a rectangular surface within the outer metallic strip, since there is a conductor in the middle and the system provides me and error when I start the simulation.

So what should I do to define an excitation for a CPW?

Please help me!

I would use a wave port large enough to include both side ground planes and the center "driven" trace. You will need to create an impedance line between one of the side grounds and the center.

Read the section in HFSS help on impedance calculations as there are additional considerations.

After I finish I like to check the calculated Zo with another tool or a manual calculation just to make sure that I did not blunder.

Simon or Waddell are useful transmission line references. I assumed from your question that the CPW you are studying does not have a cover or additional groundplanes.

hi,

draw a box such that one of the face of box exactly touches the CPW three terminals. Your structure must be totally enclosed in that box. the distance from the antenna patch plane to top face of the box should be lamda/10. make the face of the box touching the three terminals of cpw as port 1 and oppsite face of box as port2 and simulate....

kishorrr........

theres a tutorial i posted in the Electromagnetic simulation forum about exciting a cpw.

You'll find that helpful.

Have a look at the tutorial attached.