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.