Learning Forum

[Jacob Randall]

I did a simulation comparison between grounded coplanar waveguide (GCPW), GCPW with vias, and microstrip. I was surprised to find that microstrip performed better at mmwave in an air radiation boundary than GCPW which contradicts literature. The questions are asked at the following link.

https://community.ansys.com/?status/49587-49587-1684238778/

Help with these questions is much appreciated. 

Jacob 

[DMARATHE]

Hi Jacob,

Thanks for posting your query on Ansys learning forum.

I will be able to provide answer to the first query. To simulate, GCPW line please follow below guidelines with respect to port sizing and creation (considering the waveport)

• The port bottom edge should lie on the substrate bottom ground plane
• There should be a contact of the port outline with side grounds & bottom ground
• The wave port size (width and height) should not exceed wavelength/2, to avoid a rectangular waveguide modal excitation
• The width of the port should be 3 x (2xg+w) and height of the port should be 4xh minimum, where w is the width of the signal line/trace, g is the separation between signal line and the side grounds and h is the height of the substrate.

With respect to query 2, I agree that GCPW has better performance over microstrip at mm wave frequencies. However, in this regards, verifying the model settings is required. If you have access to the Ansys Technical Support, please raise a service request on below portal and Ansys engineer will get in touch with you. Thanks.

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