A Compact Beam-Forming Network for Switched-Beam Arrays

A Butler-matrix-inspired beam-forming network has been developed to provide phasing for a switched-beam 2×2 element antenna array. The network uses an arrangement of double-box quadrature hybrids to achieve wide instantaneous bandwidth in a small, planar form factor. The planar feed structure has been designed to integrate with an array aperture to form a low-profile array stackup.