about coax feed, please help me,thank you in advance

now i have to attach a coax cable to a microstrip line for the use of feed, as the outer conductor of the coax table is modeled as a cylinder plane , it is difficult to touch the ground plane, so i want to construct a pec path to connect them, is it right and does not affect the simulation, any indication will be appreciated!

best regards!

sanders,
can you draw a model that shows your intention.
I did the same (coax and microstrip), but I need to know whether you mention the same structure or not.

you should model a metal fixture, which is oftern used to measure the device with microstrip as input/output by VNA. SMA which is connected with the coaxial cableis is mounted on the fixture. At the same time the fixture touches with the ground of the microstrip.

hi ,burton
then how to model a metal fixture,thank you for your reply

Ans: The way you modeled the microstrip thin counductor box (strip).

I mean that you can model it in any tool you have on CST but the most important thing about it, is to set it to PEC (its supposed to be the ground connector to link between the microstrip ground and the coax ground - metalic shield).

If you have further question about it, please post a picture of it or the model itself.

Good luck :D !!!

Itzik