The present invention provides a miniature wideband antenna for 5G, which includes a dielectric substrate, a coplanar waveguide feed structure on a front of the dielectric substrate, a main radiator, a second and third radiators and a first radiator on a back of the dielectric substrate. The antenna is small in size with operation band of 3 GHz-30 GHz which covers the various 5G frequency band and covers the current wireless modes of Wi-MAX, W-LAN, UWB and so on. The antenna guarantees future compatibility for various complicated communication modes and has good perspectives for many applications. Based on the antenna, the double-unit and four-unit MIMO antenna adopts orthogonal polarization and metamaterial unit. Thus, high unit separation is achieved without increase on the size of the antenna unit. The present invention has wide applications in small mobile device such as cell phone and laptop.