A novel EDMOS device with a breakdown voltage of ∼10V and a record high RF performance, with f T ∼ 90 GHz and /MAX ∼ 450 GHz, is presented. The transistor is composed of a thin gate oxide (logic) in the channel and a thicker oxide (IO) in the drain extension. A separate dummy gate is formed on the extension region to optimize the electric field for minimizing the device degradation due to the hot carrier injection. The device concept has been intensively investigated by TCAD, and fabricated in a baseline 40nm CMOS foundry process without any additional masks. This paper discusses in detail the measured characteristics of the device, including DC, RF and the reliability. For the same operating and breakdown voltage, this device outperforms optimized Si-LDMOS and SiGe HBTs in both f T and f Max , and is on par with the best-in-class GaN-HEMTs in term of f Max .