## 1. Introduction

[2] The electromagnetic (EM) interaction of multiconductor transmission line structures with high frequency EM sources (up to several GHz) becomes an increasing topic of current research. This is due to a rapid development in the information and communication technology and the accompanying necessity to guarantee a smooth EM operation of all connected devices and systems. Since radiation phenomena occur more frequently and lead to EMC-relevant perturbation effects, they have to be included in the EM analysis of electrical and electronic systems. In particular, the effective simulation of new systems in the design phase becomes a cost-saving factor. There, the demand for numerical programs which can efficiently calculate the interaction of complex EM systems with high frequency fields is one resulting consequence. In this context the use of the telegrapher equations for nonuniform multiconductor transmission lines [*Nitsch and Gronwald*, 1999; *Baum and Steinmetz*, 2003] seems to be an adequate means. They have to be, however, extended to become valid for arbitrary frequencies and modes. This was done by *Haase and Nitsch* [2001]. Different from their approach, in the present paper we deal with a simple line configuration, an infinite, uniform transmission line above a perfectly conducting ground, and show that the Maxwell equations for this line can be cast into the form of the telegrapher equations, by keeping the source fixed but changing the classical line parameters to generalized, complex-valued ones.

[3] In section 2 we calculate the new line parameters in a gauge-independent way, using the Helmholtz decomposition [*Cohen-Tannoudji et al.*, 1997] for the electric field. Their relation to the radiation resistance is established on the basis of a Poynting vector analysis for the radiating infinite line (section 4). We also perform a quasi-static approach for the infinite line (section 3) and obtain solutions without radiation fields. In particular, the corresponding parameters are real.

[4] Our generalized description of transmission lines can be extended to include multiconductor lines of finite length with losses [*Haase at al.*, 2004]. Then, when incorporated into an existing field-theoretical computer program for complex systems as a module for very efficient calculations of linear structures, simulations of electronic systems in the GHz-regime become essentially faster. The present paper, in a first step, gives insight into new physical phenomena which are connected and inherent in the new parameters.