An ultra-wideband square patch antenna with resonance frequency at wide range from 1.8 GHz to 7 GHz has been designed with the application of metamaterial block. Without the application of loading any metamaterial and its equivalent block, the square patch antenna resonates at 4.22 GHz and 5.6 GHz while an introduction of dual circular ring resonator as its metamaterial and its derived equivalent block, the resonance frequency range becomes widespread with a similar gain and efficiency. The effect of dual ring resonator and its derived block at ground layer provides a mechanism for the patch size reduction from 39.32 mm to 17.02 mm (about 81.26 % reduction in its area). The equivalent block of the metamaterial has been obtained after deriving the relative permittivity and permeability of the circular ring resonator metamaterial and its effect has been also analyzed.