Propagation characteristics of high-frequency currents on ground wires

Recently, it was pointed out that high-frequency currents in a ground wire can be a cause of malfunction of information and communication devices. In order to understand the behavior of high-frequency currents in a ground wir e, the currents flowing in the ground wires of information and communicatio n devices were measured. The measured high-Frequency ground current may rea ch 250 MHz. In the case of information and communication systems, the groun d wire from each device is connected to the grounding terminal plate (coppe r plate) that is connected to the building grounding via a grounding bus. I n the present research, a transmission line model is developed for the case where the grounding wires from various devices and the grounding bus are c onnected to the grounding terminal plate. From model, experiments, calculat ions with an equivalent circuit based on the model, and experiments with an actual system, the propagation characteristics are discussed. (C) 2000 Scr ipta Technica, Electron Comm Jpn Pt 1, 84(1): 77-83, 2001.