This paper primarily focuses on the design and analysis of uniform circular array of four planar horn antenna elements with a perspective of optimizing them at frequency of 70 GHz. The four horn antenna elements are placed at an angle separation of 90degrees. The four antennas are connected via a coaxially fed four-port equal power divider circuit. The array is designed for millimeter wave frequency (60-90 GHz) application. Aluminum is used as conductor for radiating elements and ground while polyimide was used as the substrate. The proposed array has very sensitive feed line width that is able to change the resonance frequency. The proposed antenna design is simulated and analyzed for Multi Input Multi Output (MIMO) and Orbital Angular Momentum (OAM) applications in E band. © 2021 IEEE.