Numerical Investigation of the Stochastic Field-to-Wire Coupling to Transmission Lines with Small Bend Angles

Abstract

This work deals with and combines two important topics of electromagnetic compatibility. First, there exist so called stochastic electromagnetic fields, like they occur in overmoded cavities like reverberation chambers or e.g. satellite bodies and airplanes [1]. On the other hand, this work focuses on transmission lines (TLs), as they may act as receiving antennas. Transmission lines often do not run in a straight line, but must be bent or curved due to environmental restrictions. In [2], the field-to-wire coupling to bent and curved transmission lines was investigated via measurements in a reverberation chamber. It has turned out that for large bending angles there are nearly no changes in the coupled voltage. For bending angles smaller than 30°, however, interesting effects occur. These smaller bending angles will be examined in more detail in this paper. Furthermore, it was found out that the bent and the coupling of the conductors must be taken into account in the transmission line model, which is based on the BLT-equations (named after Baum, Liu and Tesche) [3]. For the investigation, a single conductor transmission line (SCL) over a conducting ground plane is considered, which is terminated at the beginning and at the end with a certain load. Now, the coupled voltage for different bending angles shall be investigated with the help of simulations in CONCEPT-II. Moreover, the bent in the already existing simulation model from [3] is taken into account using a location-dependent characteristic impedance.