Abstract-Based on the active coupled line concept, a novel approach for efficient noise performance modeling of millimeter-wave field-effect transistors is proposed. This distributed model considers the effect of wave propagation along the device electrodes, which can significantly affect the noise performance especially in the millimeter-wave range. By solving the multi-conductor transmission line equations, using the Finite-Difference Time-Domain technique, this procedure can accurately determine the noise correlation matrix of the transistor and then its noise performance.