Experimental Realization of Bespoke Multi-Band GRIN Lens Using Multi-Objective Optimization

Gradient index (GRIN) lenses are powerful tools to improve the directivity of antennas. However, traditional GRIN designs are typically limited to single-band performance and small index variations. In this paper, we propose a multi-objective optimization strategy for designing GRIN lenses for multi-band operation, where the two targeted bands are widely separated. Using additive manufacturing, a typical lens prototype is fabricated and tested, demonstrating excellent dual-band performance.