In this paper, metamaterials are used, in order to verify their utilities; two different structures have been considered as a ground. The first one is a mushroom EBG (Electromagnetic Band Gap) structure which is composed of several patches with a ground connecting via, where the second one is a 2D metamaterial structure with resonant rings and digital capacitors. CST, which is based on one of the most popular numerical method Finite-Difference Time-Domain (FDTD) is used. Both the structures are investigated by simulation and compared at the frequency of 12 GHz, the metamaterials properties are successfully verified around the resonant frequency. A very low cost wire is transformed into a valuable circuit by enhancing the directivity and the gain in order to rival other antennas, in order to ensure a large use to the dipole. The digital capacitor has essential part in this work. The antenna proposed in this work is in the frequency band Ku.