Orbital angular momentum (OAM) of electromagnetic (EM) waves is characterized by a helical phase front, which is significant for its potential to enhance communication systems through orthogonal modes. This paper explores the generation of an OAM beam using a transmitting-type metasurface. A unit cell is designed with three copper layers cascaded by two dielectric layers of Rogers RT5880 with a permittivity (ϵ) of 2.2 and a loss tangent (tan δ) of 0.0009. This multilayer structure enables a full 360 -degree phase variation for both x and y-polarized EM waves, achieved by varying the length of the metallic element in the unit cell. A horn antenna is designed as the feed source for the proposed metasurface, with an optimized focus-to-diameter (F/D) ratio of 0.81. Using a 21 × 21 array of unit cells, the transmit array metasurface can generate an OAM beam with modes = ± 1 and ± 2 in the 2734 GHz (24.7 % bandwidth) band with a divergence angle of 9.5 and 16 degrees, respectively. Furthermore, the metasurface successfully generates OAM beams with a high mode purity for both polarizations.