Interference from Unshielded HV Harnesses with Realistic Groundplane Models

Abstract

In a vehicle, unintended electromagnetic coupling among sensitive components such as antennas etc. needs to be suppressed to prevent the interference to cables. The cables for power and signal transmission are, therefore, only allowed to be packed in each other’s vicinity after proper shielding. As the shielding decreases the payload for a given vehicle design and increases its cost, it is very relevant to shed light on alternative packaging omitting shielding completely. Accordingly in this report, computations based on 3-dimensional transmission line matrix method will be launched to execute parameter sweeps comprising intercable distance, cable distance to groundplane, cable length, and signal cable termination impedance. A Vector Network Analyzer based experimental study to verify the computational approach is presented. Subsequently, crosstalk effect of realistic groundplane from a vehicle concept is also compared to a simple planar groundplane using 3D Transmission Line Matrix approach. It will be shown that the crosstalk will be kept below the limits as specified by the standards and internal OEM requirements with minimal intercable spacing, eliminating the cable shielding while reducing the environmental footprint.