Metamaterial waveguide device and method for improving signal-to-noise ratio of radar system capable of reducing ionospheric interference reflections and increasing detection distance and tracking stability of the target

Provided is a metamaterial waveguide device for improving the signal-to-noise ratio of a radar system, wherein the metamaterial waveguide device includes: a main body in which a plurality of thin wires are arranged, wherein the plurality of wire lines are embedded in the main body in parallel, and there is a distance between each thin wire and another one; and a bottom layer attached to the lower part of the main body. With the metamaterial waveguide device, its equivalent dielectric constant is made to be negative in the frequency range, so as to generate a surface wave mode for performing a mode matching with the mode supported by the environment around the radar.