Patent attributes
A first conductor is provided on an outer circumference of a central conductor with an insulator therebetween, a second conductor is provided on a concentric circle having the central conductor as its center and outside the first conductor with an insulator therebetween. A coaxial cable is formed by coating the outside of the second conductor, which is on the concentric circle having the central conductor as its center, with an insulating external coating. A DC voltage source is able to apply DC voltage having a predetermined voltage value between the first conductor and the second conductor such that the direct current flowing in the first conductor and the second conductor takes a desired value. A noise barrier zone formed by the electro-magnetic action of the desired current is formed in the part surrounded by the first conductor and the second conductor on the outer circumference of the central conductor.
