Radiation from transmission lines PART I: free space transmission lines

Abstract

This work derives exact expressions for the radiation from two conductors non isolated TEM transmission lines of any cross section in free space. We cover the cases of infinite, semi-infinite and finite transmission lines and show that while an infinite transmission line does not radiate, there is a smooth transition between the radiation from a finite to a semi-infinite transmission line. Our analysis is in the frequency domain and we consider transmission lines carrying any combination of forward and backward waves. The analytic results are validated by successful comparison with ANSYS commercial software simulation results, and successful comparisons with other published results.