How to define a Coplanar Waveguide Port in HFSS

[DDRio]

define coplanar

Hi!

I'm trying to simulate a Folded Slot Antenna using CPW feed and I'm wondering what is the type of port that I need to use to define it as CPW port. As an attachment I include the HFSS file. I used a waveport and defined two modes for the two strips. But now I see the results and they do not look like the results on designer. In fact, they look extremely different. The main problem here is that I don't know how to define the port. I draw two rectangular strips on one of the faces and define an integration line on each of them.

Please take a look and let me know what I'm doing wrong. And if you are going to send files, send them to daviddrio@yahoo.com. I don't have enough points to download the attachments from this board.

Thank You!

 

[gregb3d]

hfss waveguide port

Hi,

First check if you're using a grounded or ungrounded cpw. Here are the rules of thumb that i have used with good results to define the box for my port:

ungrounded:
make box width=3(2g+w) and height= 4h (start a little below substrate)

grounded:
make box width=3(2g+w) and height=4h (starting at top of gnd plane)

where, w=width of center conductor, g=conductor spacing, h=substrate thickness

In both cases the box should be centered

good luck