Graded Dielectric Metamaterial with Designable Permittivity Fabricated by 3D Printing

The increasing demand for electronic devices operating in specific frequency bands (e.g., X-band dielectric resonator antennas) has driven the development of materials with precisely tunable permittivities. Metamaterials with artificially engineered microstructures are promising for tailoring the effective permittivity to meet application-specific requirements. By leveraging the high precision of 3D printing, this work achieves precise control over the effective permittivity by accurately adjusting the geometric parameters of metastructures and establishes a permittivity prediction model for composite materials using effective medium theory. The application-driven design of a graded dielectric metamaterial is demonstrated through an X-band dielectric resonator antenna with the following significant performance improvements: a broad bandwidth (6.2 GHz) covering the entire X-band (8–12 GHz), whereas the conventional bandwidth is only 1.7–4.2 GHz, and a gain value of 14.7 dB. This study paves the way for the development of high-performance antennas, radio frequency components, and frequency-selective devices with enhanced frequency adaptability and integration.