A DPC-GJC Matrix Enabling Independent Reconfigurable 2-D Multibeam Scanning

This article presents the first generalized joined coupler (GJC) matrix-based architecture capable of simultaneously generating multiple independently steerable beams in 2-D. Built upon a conventional single-layer GJC matrix, the proposed dual-phase-controlled (DPC) GJC matrix introduces two independently tunable phase-control sets to realize decoupled beam steering in the azimuth and elevation planes. Unlike existing matrix-based beamforming networks (BFNs) that rely on stacked multilayer structures for 2-D beam scanning, the proposed architecture achieves 2-D multibeam scanning within a single-layer topology, significantly reducing hardware complexity and implementation cost. An inverse coupler synthesis (ICS) method is developed to optimize the coupling coefficients of the matrix. Numerical results demonstrate that the proposed matrix can generate multiple independently steerable beams and can be flexibly mapped to different antenna array configurations without modifying the hardware structure. To validate the concept, a fully integrated4× 8prototype is implemented using a folded multilayer PCB incorporating phase shifters, gain-compensation amplifiers, and an FPGA-based control module. Experimental results demonstrate simultaneous multibeam generation with independent steering in both azimuth and elevation, with a maximum gain variation of 2.6 dB and sidelobe levels below −8 dB.