DRA Overlapping Function Hardware Implementation Via Waveguide Beamformer

In the work at hand we present the design procedure of a waveguide beamformer network that implements the Direct Radiating Arrays' Overlapping Function. Such a design is notorious for its complexity and challenge since it should deliver wideband, dual polarization overlapped feeding to planar antenna arrays. Such a feeding network is to be viewed as a building block that would tile the background, on top of which the fed sub-array antenna elements would respectively tile the radiating aperture host area. Thus, each feeding network should provide ports on the lower face, (input feeding ports), the upper face, (input to antenna elements), but also to the side faces to provide overlapping. Here, utilizing transmission matrix factorization, the beamformer is designed as a cascade connection of elementary components, hybrids and phase shifters. The 3d actual implementation of the multiport network in a rectangular waveguide technology, supporting both polarizations, is indeed challenging. In the current work such a device is presented and its merit is demonstrated.