Abstract: A chip package includes a set of layers including conductive planes connected by vias. A first portion has at least one antenna, antenna ground plane, and first grounded vias. A second portion has a conductive plane parallel to the ground plane that forms an interface for connecting to at least one integrated circuit device. A third portion between the first and the second portion has a vertical transmission line that includes a signal via connecting the antenna feed line to the at least one integrated circuit and a parallel-plate mode suppression mechanism. The parallel-plate mode suppression mechanism includes a grounded reflector that forms a cage with the grounded vias around an antenna region and further includes second ground vias surrounding the signal via.