This new transistor is based on a nano-wire structure. The channel of the transistor is made of a nano-ribbon shaped material, instead of the planar large-area quantum well or two dimensional electron gas (2DEG) typically used in these devices until now. The proposed structure can be implemented on III-N wafers grown both N-face and Ga-face. To achieve high breakdown voltage, special junction termination techniques are used to control and shape the electric field at the edges of the devices. These techniques include field plate, guard rings, bevel edge termination and junction termination extension. The fabricated transistor demonstrated a threshold voltage of 1V and a specific on resistance of 0.36 mΩcm2. By proper electric field engineering, 800 V blocking voltage was achieved at a gate bias of 0 V.