s11 antenna using CST, not working? Any help ?

[abuantenna]

Hello,

I tried to re-produce the results for one published slot antenna using MW CST. The reults for s11 is very far from what is in the paper.
They did that using HFSS. I thought it will be possible using CST as well.
Could anyone try that using CST or HFSS please ?

Regards

 

[adel_48]

Hi,

are you sure your dimensions are correct? the substrate looks very thick

Also, to reproduce the results you may need to model the shape of the feed.

hope this will help,
Adel

 

[abuantenna]

Yes, I agree. But this exactly what they mentioned. It is 400 um.

For the feeder: I think it should be no problem. I checked the input impedance and it is about 50 Ohm as they wrote in the paper.
So, it should be ok.

May be it is the effect of lens ?? I have no lens in my design, and they have it there as I can understand.

Added after 42 minutes:

It seems the problem in the port dimensions.

I checked the shape of the e-field and it looks not nice. I tried to to follow CST guidlines but they are not working with such dimensions.

Any help for good dimensions ?
Ungrounded CPW with 20 um signal line and 24 um gap.

Added after 36 minutes:

I solved the probelm. It seems that I have to choose some specific dimensions for the port with some special boundry conditions.

I used open from xy directions and open add space or top and bottom. It seems now much better.

Thankks