Transmission Line Model of EMP Coupling with Star-Quad having Central Reference Conductor

In this paper, a multiconductor transmission line model is developed for characterizing the coupling of electromagnetic pulse (EMP) with the star-quad cable having a central reference conductor. Expressions for voltages and currents are given for both left and right terminations of the cable. The given model generates the induced common-mode (CM) and differential-mode (DM) currents when the star-quad cable is excited by the EMP. In addition, a comparison is established between the star-quad above the ground plane and the star-quad with the central reference conductor, which shows that in the case of the central reference conductor, the induced CM current is comparatively very less. Also, the radiations for the star-quad with central reference conductor are far less than the star-quad above the ground plane. The results of our proposed model are in good agreement with the results of the commercial software FEKO.