Electromagnetic wave selection cover for reducing same-frequency interference

An electromagnetic wave selection cover for reducing same-frequency interference adopts corresponding electromagnetic wave blocking materials to surround an antenna and is provided with an electromagnetic wave signal inlet and outlet, so that the electromagnetic wave selection cover is formed, and under the condition that the wavelength condition meets the condition that the antenna enters the signal inlet and outlet, the signal intensity is enough or the intensity is not completely enough but the direction is proper. Or electromagnetic waves which are not completely suitable in direction but good in intensity condition can enter the cover to communicate with the antenna, so that the interference of other electromagnetic waves outside the cover on the antenna in the cover is reduced or eliminated. The size of the inlet and outlet is larger than one fourth of the wavelength of electromagnetic waves (electromagnetic waves for antenna communication in the cover) in only one direction and smaller than one fourth