TLM diakoptics for coupled-mode analysis of GaAs MESFET distributed amplifier

A new model of the application of diakoptics in the transmission-line-matrix (TLM) method for the coupled-mode analysis of GaAs MESFET distributed amplifiers is proposed. The model takes into account the major coupling effect caused by C-dg and g(m), of the active devices. Techniques are developed by representing the whole system as two coupled lossy transmission lines. The numerical effort required can be reduced by representing the response of the resultant coupled system as that of a superposition of two independent modes. The scattering matrix of the system obtained in the time domain leads to a process of discrete time domain convolutions based on the TLM numerical procedure. The results are compared with other analytical and computed results and show good agreement.