Multibeam Pattern Synthesis Techniques for 5G and Beyond Wireless Communications

Multibeam radiation patterns play a crucial role in 5G and beyond wireless communications. This paper presents two multibeam pattern synthesis methods. The first is the beam-partitioned iterative Fourier transform (BP-IFT) method, designed for large reconfigurable intelligent surfaces (RISs) synthesis. The BP-IFT method achieves precise peak direction and power control by partitioning the multibeam pattern into single-beam ones and calibrating each individually. The second method is a sequential coupler and phase optimization (SCPO) approach for an analogue beamforming network (BFN), specifically the generalized joined coupler (GJC) matrix. Leveraging particle swarm optimization (PSO), this approach sequentially optimizes directional couplers and phase shifters to enhance multibeam performance, including sidelobe level reduction. Numerical examples are provided to demonstrate the effectiveness and efficiency of both methods.