This paper addresses the design of an antenna array for a portable picocell station with omnidirectional coverage. The proposed solution includes a stacked patch antenna as a single radiating element of the antenna array and a hybrid beamforming network. The antenna element works at 26 GHz with a bandwidth of 20% and a gain of approximately 8.5 dB along the operational bandwidth. The antenna is fed by a suspended stripline transitioned from a waveguide. This antenna element is used to compute a 5x12-element antenna array fed by the hybrid beamforming network. Results are analytically obtained for a fixed analog beamforming network that generates a csc squared pattern shape in elevation. Additionally, a digital beamforming network is computed to perform beamsteering for a desired set of constraints in the azimuth plane. Simulated results of the complete system yield promising insights on the capacity of the proposed design to provide omnidirectional coverage.