<p>This work presents an array of slot-type elements fed by a corporate network, achieving several radiation patterns in the mm-Wave band. The antenna is based on a metal-only structure, with a feeding network implemented using Groove Gap Waveguide technology, resulting in a low-loss, highly scalable solution. The radiating elements are slots in a 1 × 8 array configuration, which are excited through three waveguide ports. The proposed feeding network allows for a sum pattern that can also steer the beam depending on the feeding port. Additionally, a difference pattern can be obtained. The proposed design is manufactured using metal-only additive manufacturing with Laser Powder Bed Fusion. The prototype is measured in an anechoic chamber, showing a high agreement with simulation for each possible pattern. Furthermore, the antenna is evaluated in a planar range, demonstrating the high isolation of the proposed Groove Gap Waveguide. Overall, the antenna exhibits over 90% efficiency and four different radiation patterns, making it an attractive solution for mm-Wave antennas in multifunctional applications.</p>