Hello Azita,

check this links.

https://www.researchgate.net/post/How_can_I_design_CPW_port_in_CST_Any_specific_example_please

Best regards

Try reading an example about a PCB antenna provided in Help topics of CST.

@chaouki

thank you dear. you know i try it before, but it doesnt work. it is strange for me. my simulation has a good result in HFSS but in cst it is very bad. i am confused.

@EKajit

thank you. would you give me more explain?

Azita

Your waveguide port should encompass the whole cross section of the CPW - both transmission lines and also the ground plane, in case it exists.

Another point to be stressed is the multipin port - when setting the WG port you should tell which mode is to be supported by the structure. Typically, you assign a (+) to the signal line, whereas the other ground conductors should be assigned as (-), the differential mode. Do it and run the solver with "port modes only" checked - once its done check if the computed mode pattern and its impedance is the one youre expecting.

@marcelo

thank you dear professor.

i cant understand the + and - sign? how can i do this in my simulator?

best regards

Hi Azita

I added some slides for you to see. They contain the description of the subject matter. See if its alright pls.

Hi,

please check this

the waveguide port should contain ground and also the strip line. in the simulations I choose the port width about 2.5 times of the strip width and the hight about 4 thimes of the height(4 times of the distance between the strip and ground)   

@vahid

thank you. but the total gain is incorect, this is the other problem. 

thank you