This paper presents a high directivity beamformer for the millimeter-wave (mmWave) base station application. The beamformer is capable of generating high directivity radio beams along azimuth and elevation planes. Beamformer structure consists of a spherical constant--dielectric lens created from plastic material, while the lens is fed by multiple rectangular horn feeds that are individually connected to mmWave radio sources. The lens structure can be machined out from plastic raw material while the feed network of the beamformer can be 3D printed and metallic plated, making the proposed beamformer structure a good candidate for mass production. Prototype beamformer is developed for 28 GHz mmWave 5G communication band, while it is scalable to even higher frequency mmWave 5G bands (39 GHz) using the same synthesis approach discussed in this paper.