A high performance 8-input, 8-output Butler matrix beamforming network for ultra-broadband applications

A lightweight, 2-18 GHz, 8 /spl times/ 8 multilayered stripline Butler matrix which exhibited superb performance is presented. The Butler matrix's excellent performance is attributed to its high-performance hybrids and phase-shift networks. The novel design techniques for the hybrids and phase shift networks are described. >