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