In this paper, a new design of a slotted bow-tie antenna is proposed. The proposed antenna operating frequency is 28 GHz which is a candidate standard for millimeter waveband and 5G technologies. The proposed antenna has been designed and simulated using five different substrate materials for two different substrate thicknesses. The obtained results are compared and tested until an optimal design is reached. The dimensions of the proposed antenna are optimized at separate times using the parametric optimization technique to get the smallest size with high efficiency. The return loss, voltage standing wave ratio, the 3D polar plot and the gain of the antenna were simulated. Simulation results demonstrate that the proposed design has good radiation characteristics at 28 GHz. Proposed antenna design can be used for future 5G devices.