Method of improving EM field distribution in a small room with an RF radiator

A method of controlling the field distribution in a room is proposed to improve the electromagnetic (EM) environment in a relatively small room compared to the wavelength of an RF radiator such as a medical treatment device. For this purpose, this paper investigates a method of realizing both a region of weak and strong electric fields in the room by adjusting the material constant of the room or by changing the shape and arrangement of ceiling, walls, etc. This idea is based upon the principle that an electric field concentrates on materials with a large permittivity. The electric field distribution is analyzed using the finite-element method to understand the effects of concentrating the electric field by taking into account many factors as parameters. To examine these in a qualitative investigation, electric field distribution is verified using a reduced-scale model. Further, on the basis of these concepts, a shielded room is constructed. It is clarified that the electric field distribution in the room is effectively controlled using the method proposed.