An antenna based on a metamaterial, comprising a radiation source, and a metamaterial panel capable of converging electromagnetic waves and operating at a first wavelength, wherein the metamaterial panel is adapted to convert the electromagnetic wave radiated from the radiation source into a plane wave and to enable the antenna to simultaneously operate at a second wavelength and a third wavelength which are shorter than the first wavelength, and the first wavelength is different multiples of the second wavelength and the third wavelength; the metamaterial panel comprises a plurality of core layers and a plurality of gradient layers (1, 2) symmetrical distributed at two sides of the core layers, and each of the core layers and the gradient layer (1,2) comprises a sheet-like substrate and a plurality of man-made microstructures attached on the substrate; wherein each of the core layers has the same refractive index distribution, and comprises a circular region and a plurality of annular regions concentric with the circular region, refractive indices in the circular region and the annular regions decrease continuously from n p to n 0 as the radius increases, and the refractive indices at a same radius are equal to each other; wherein each of the gradient layers (1, 2) located at a same side of the core layers comprises a circular region and a plurality of annular regions concentric with the circular region, and for each of the gradient layers, the variation range of the refractive indices is the same for all of the circular region and the annular regions thereof, the refractive indices decrease continuously from a maximum refractive index to n 0 as the radius increases, the refractive indices at a same radius are equal to each other, and the maximum refractive indices of any two adjacent ones of the gradient layers (1, 2) are represented as n i and n i+1, where n 0 <n i <n i+1 <n p, i is a positive integer, and n i corresponds to the gradient layer that is farther from the core layers. the metamaterial panel comprises a plurality of core layers and a plurality of gradient layers (1, 2) symmetrical distributed at two sides of the core layers, and each of the core layers and the gradient layer (1,2) comprises a sheet-like substrate and a plurality of man-made microstructures attached on the substrate; wherein each of the core layers has the same refractive index distribution, and comprises a circular region and a plurality of annular regions concentric with the circular region, refractive indices in the circular region and the annular regions decrease continuously from n p to n 0 as the radius increases, and the refractive indices at a same radius are equal to each other; wherein each of the gradient layers (1, 2) located at a same side of the core layers comprises a circular region and a plurality of annular regions concentric with the circular region, and for each of the gradient layers, the variation range of the refractive indices is the same for all of the circular region and the annular regions thereof, the refractive indices decrease continuously from a maximum refractive index to n 0 as the radius increases, the refractive indices at a same radius are equal to each other, and the maximum refractive indices of any two adjacent ones of the gradient layers (1, 2) are represented as n i and n i+1, where n 0 <n i <n i+1 <n p, i is a positive integer, and n i corresponds to the gradient layer that is farther from the core layers.