Irregular terms in the impulse response of a multiconductor lossy transmission line

Linear multiconductor transmission lints can be effectively represented in the time domain as a dynamic multiport through the describing input and tra nsfer impulse responses, Unfortunately, these responses cannot be analytica lly evaluated for the most general case of lossy lines. In addition, they c annot even be evaluated numerically due to the presence of irregular terms such as Dirac pulses, functions that actually approximates Dirac pulses, an d functions of the type 1/root t. Nevertheless, all these irregular terms c an be isolated from the regular ones. This paper proposes an analytical met hod to evaluate exactly the irregular terms. This method is based on the pe rturbation theory of the spectrum of symmetric matrices and can be easily a nd effectively applied to the most general case of frequency-dependent loss y multiconductor lines. Once the irregular parts of the impulse responses a re known, it is possible to evaluate accurately the regular ones through si mple numerical methods, as shown through some examples.