Thus, aspects and embodiments, provide a phase array antenna system that includes corner/edge effect mitigation through the use of substrates with different dielectric constants in the various patch antenna elements making up the array, with the dielectric constant being selected or tailored depending on the individual antenna element positioning within the array. Thus, the dielectric constant can be modulated based on spatial positioning with the phased array to precisely tune the self-match signals of the various antenna elements based on the level of mutual coupling experienced at different array positions. In certain examples, depending (for example) of the performance levels required for a given implementation of the phase array, the dielectric constant modulation can be applied to only a certain few of the antenna elements (e.g., only to the corner elements 200a where the edge effect is most significant), to a certain subset of the antenna elements (e.g., the corner elements 200a and at least some of the edge elements 200b and/or 200c), or may be tailored across the entire array. As discussed above, in certain embodiments, the tailored dielectric constant can be achieved by altering the density of the substrate(s) 230 using additive manufacturing techniques, which may offer several advantages. Unlike conventional corner/edge effect mitigation approaches that add RF absorber material or dummy/surrogate antenna elements and thereby add size, cost, and weight to the array, material dielectric constant modulation implemented through additive manufacturing may conveniently mitigate the corner/edge effect for small-scale finite phased array antennas without increasing the size of the array. In certain examples, introducing cavities or voids by a 3-D framing structure within the substrate lowers the density, and therefore the dielectric constant, while also enhancing mode purity with no material waste and only a minor compromise of mechanical rigidity. In addition, the additive manufacturing processes enable a smooth transition across hetero-structures to avoid charge accumulation. Using additive manufacturing, as discussed above, high-precision, mechanically robust, custom-tailored antenna elements and arrays may be created, optionally in small quantities, at reasonable cost, advantageously allowing the development of unique structures for particular applications.