In this work we assess the feasibility of fabricating a matrix of antennas for the millimeter (mm)-wave band using the “Multi Chip Module – Deposited (MCM-D)” process. The main focus of the design is to minimize the cross coupling between the antennas fabricated on the common substrate. We investigate the use of a virtual cavity formed by metalized vias in order to reduce the cross coupling to the neighboring cells. The radiation efficiency is analyzed in detail, and experimental results of a 2 × 2 array are presented.