High temperature superconductive Butler matrix beam former for satellite applications

This paper presents a novel configuration for a superconducting satellite beamforming network. The beamformer implements planar HTS 8/spl times/8 Butlers matrices with folded structures and multi-layer cross-overs. The matrix is optimized using full-EM simulation. Simulated and measured data are presented for the Butler matrix. The measurements show that the beamformer has an amplitude variation of less than 1 dB and a phase variation of less than 10/spl deg/. The proposed layout of a complete beamformer with sixteen 8/spl times/8 Butler matrices is given with performance comparisons to multi-layer and co-axial technology.