Alternative analysis method of lumped-element circuit model for transmission lines

This Letter presents an alternative analysis method to derive the voltage-current transmission matrix of transmission line sections. By contrast with the approach usually adopted in many microwave engineering textbooks, the proposed method, instead of coping with the telegrapher's equations and their solutions, computes efficiently the relationship between the voltages and currents at the input and output of a circuit modelled throughNidentical cascaded two-port reciprocal networks. This is implemented through the eigendecomposition of the transmission matrix of the two-port networks which are subsequently synthesised withL-sections. AssumingNas being very large, one obtains the desired transmission matrix, and additionally, it is depicted that the circuit supports forward and backward waves.