In present study, a silicon on insulator metal-semiconductor FET (SOI MESFET) with embedded metal and L-shaped oxide layers (EMLO) is introduced. This structure consists of two-part oxide section (stepped) in the channel area and a nickel-metal layer in the upper part of the buried oxide, where the dimensions have been optimized to achieve the proper result. We named this structure briefly as EMLO-SOI MESFET. The performed simulations show that the presence of the mentioned variations causes noteworthy enhancement in breakdown voltage. The additional oxide sheet at the top of the channel has greater critical electric field than silicon. Also, the metal layer scatters the potential lines at the edge of the gate and inside the drift layer. As a result, the breakdown voltage experience 41% improvement. Drain current also increases by 42% in the proposed structure. The study on the maximum output power density shows 108% increase for new structure. The result reveals that both maximum oscillation and cut-off frequencies are increased by about 23% compared to the conventional structure. This improvement in RF parameters is due to the modifications in GS and DS capacitances.