3-D Printed All-Dielectric Ultrabroadband Microwave Absorber

A dielectric resonator-based ultrabroadband microwave absorber is proposed. The first and second iterations of the Minkowski fractal are exploited to design the final unit cell geometry. The final prototype is an all-dielectric microwave absorber and is fabricated using 3-D printing technology. Conventional microwave absorbers are usually made up of metal, dielectric, resistive, or active components, while the proposed absorber is fabricated using just dielectric material, hence the name all-dielectric. This all-dielectric absorber offers absorption from 2.54–40 GHz at normal incidence. For TE mode, absorption is stable up to 40<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> and up to 60<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> for TM mode. The ultrawide band with its −10 dB fractional bandwidth up to 176<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\%$</tex-math></inline-formula> is achieved using single technology and one-step fabrication. Measurement results are in good agreement with simulation. The presented work opens new dimensions to explore all-dielectric mechanically robust microwave absorbers. Therefore, it is suitable for use in harsh environments without any post-processing treatment.