Equivalent Pi-network model of lossy and dispersive coupled transmission lines

An equivalent circuit representation is presented for a set of coupled transmission lines. An approximation of the hyperbolic secant function allows a simple derivation of a staged model that accounts for the complex frequency dependent parameters. The model converts the T-ladder network into a Π-network with controlled sources. The equivalent circuit based approach presented here is not only intriguing but also enhances the computed accuracy and efficiency. Numerical simulations verify the accuracy of this approach for both time and frequency domain responses.