Possibility of the reduction of the electromagnetic noise of the shinkansen (bullet train) by installing conducting nets

Abstract

AbstractElectromagnetic (EM) noise is radiated when electric trains run along the Shinkansen and the VHF content causes TV receiver jamming. Currently a shared receiving method is put into practice for anti‐jamming. The jammed area extends several hundred meters to each side of the railroad, but if the noise can be reduced by 6 dB the area will be narrowed by a factor of 3 to 4. Earlier noise reduction methods were: improvement of pantograph structure, change of rubbing plate material and use of ferrite in key parts of the pantograph. However the problem on both sides of the railroad remains difficult to solve. In this paper we propose that conducting nets be installed on the supporting poles of the trolley wires. With a net three meters in width, calculation shows that the noise at 150 MHz can be reduced by 6 dB. In the calculation the noise source is taken to be a point source and the field is determined by superposing the waves diffracted from the upper and lower edges of the nets. The calculated results have been verified by experiments with a 1/70 reduced scale model.