How to add transistor models in ADS TOOL

It is not clear what you want/need. Do you want to add a transistor manufacturers library (Designkit) or do you want to define a transistor from the transistor model parameters (netlist/text based)?

its relate to design kit

The procedure to install and use the designkit in ADS 2011 is described in the online help in topic "Working with Upgraded PDKs in ADS 2011"
If you use ADS 2011, you will need a designkit that was upgraded for ADS 2011. Earlier designkits (2009 and before) can not be used with ADS 2011.

申明：网友回复良莠不齐，仅供参考。如需专业帮助，请学习易迪拓培训专家讲授的ADS视频培训课程。