Problem with ads port configurations

[rututu]

hi everyone

I want to design a circuit with cpwg lines at 26Ghz. my problem arises when I have to define the ports. so I have documented the port configurations with the following document: https://literature.cdn.keysight.com/litweb/pdf/5992-0415EN.pdf

in this document, it is mentioned that the distance between the plus and minus pins smaller than 10% of the wavelength at the highest simulation frequency.

My frequency is 26 Ghz so I calculated the maximum distance between the plus and minus pins which is 1.15 mm.

However on my design, the distance is 0.88mm but I get the following error : The distance between the layout pins for port 1 is electrically large above 18.2075 GHz, S-parameters may become unphysical.

I used edges pins for the ground on each side and a normal pin for the transmission (see picture)

Despite my research on different forums I can't find a solution to solve this problem.

can you help me, please.

 

[BigBoss]

ADS warns you about the thickness of the substrate because there is a hidden GND Port just underneath the real Port.
If the electrical length that is lambda0/sqrt(epsR) larger than c0/ max. frequency, ADS gives you a warning..

Secondly, if the VIAS are connected to GND, don't place the Ports for them..

 

[rututu]

Okay, thank you for that clarification.
Indeed, the vias are connected to GND. if I understand correctly I do not need to use the edges pins for the ground, only a normal pin is enough.

can you please confirm if this is right.

 

[BigBoss]

Okay, thank you for that clarification.
Indeed, the vias are connected to GND. if I understand correctly I do not need to use the edges pins for the ground, only a normal pin is enough.

can you please confirm if this is right.

Yes, that's right.. Otherwise there is no sense at all to place the VIAS right ?? ADS Momentum presumes the GND Layer is infinite,ideal and everywhere unless a special case defined.