#439 OpenEMS TLine Example and TLines in SG13G2 Issue created by EngGhaith Hi Everybody! In the example you have provided about simulating TLines with openEMS I have observed, that there is a SiO2 above the top line Metal: [Image](https://private-user-images.githubusercontent.com/178785944/431397085-c0547513-5b84-482c-9fcc-ef016e2ffdbe.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJnaXRodWIuY29tIiwiYXVkIjoicmF3LmdpdGh1YnVzZXJjb250ZW50LmNvbSIsImtleSI6ImtleTUiLCJleHAiOjE3NDQzMjM5NjcsIm5iZiI6MTc0NDMyMzY2NywicGF0aCI6Ii8xNzg3ODU5NDQvNDMxMzk3MDg1LWMwNTQ3NTEzLTViODQtNDgyYy05ZmNjLWVmMDE2ZTJmZmRiZS5wbmc_WC1BbXotQWxnb3JpdGhtPUFXUzQtSE1BQy1TSEEyNTYmWC1BbXotQ3JlZGVudGlhbD1BS0lBVkNPRFlMU0E1M1BRSzRaQSUyRjIwMjUwNDEwJTJGdXMtZWFzdC0xJTJGczMlMkZhd3M0X3JlcXVlc3QmWC1BbXotRGF0ZT0yMDI1MDQxMFQyMjIxMDdaJlgtQW16LUV4cGlyZXM9MzAwJlgtQW16LVNpZ25hdHVyZT1lNTU3YmM2Y2E0Y2Q4ZmZjZjM4ZDk3N2FkMTgzMjM2N2Q0MjY3NDRjYTE4NTk0MmNlMjg3YjBjZGE2ZWMyNTMzJlgtQW16LVNpZ25lZEhlYWRlcnM9aG9zdCJ9.3NUbXQienEtLBkNysKn9PhQ1Bge34NWnMEys2mAW7Ho) Is that right modeled? This SiO2 would change the behaviour of simple microstrip to embedded microstrip. Can we get an etched SiO2 (Passivation/Air above TM2) above th Line in your opensource PDK and how to do it in the GDS? Thank you in Advance. Ghaith Al Sabagh. IHP-GmbH/IHP-Open-PDK