Antenna package structures are provided to implement wireless communications packages. For example, an antenna package includes multilayer package substrate, a planar antenna array, antenna feed lines, and resistive transmission lines. The planar antenna array includes an array of active antenna elements and dummy antenna elements surrounding the array of active antenna elements. Each active antenna element is coupled to a corresponding one of the antenna feed lines, and each dummy antenna element is coupled to a corresponding one of the resistive transmission lines. Each resistive transmission line extends through the multilayer package substrate and is terminated in a same metallization layer of the multilayer package substrate.