3-D constrained lens beamformer for planar arrays

A 3-D constrained lens beamformer is described which is suitable for feeding a planar array antenna in which the elements are arranged upon a triangular lattice within a circular aperture. The lens can produce nine simultaneous beams from a 37-element planar array, covering an angular range of ±30° in both planes. Pyramidal horns are used for the lens beam ports and array ports. The lens design procedure makes the following approximations: the beam port horn cluster and the array port horn cluster are assumed to be in the far-fields of each other; and the mutual coupling between horns on each cluster is neglected