Distributed Modeling of 4-Port Transistor for Linear mmW Design Application

This paper presents an approach for the distributed modeling of a 4-port transistor. The proposed principle relies on considering any multi-finger transistor as the association of a number of elementary active linked together with extrinsic passive networks. An electromagnetic analysis allows to set the electrical equivalent scheme of the passive networks whereas the internal active device is defined by an equivalent model. It is shown how the equivalent intrinsic device (based on 2 fingers) and the values of the suitably defined distributed parasitic network elements can be accurately extracted and modeled on the basis of standard measurements. This approach is validated by the comparison of measured and simulated results for a GaAs HEMT transistor in the Ku-band.