3D-Printed Low-Cost Dielectric-Resonator-Based Ultra-Broadband Microwave Absorber Using Carbon-Loaded Acrylonitrile Butadiene Styrene Polymer

Abstract

In this study, an ultra-broadband dielectric-resonator-based absorber for microwave absorption is numerically and experimentally investigated. The designed absorber is made of the carbon-loaded Acrylonitrile Butadiene Styrene (ABS) polymer and fabricated using the 3D printing technology based on fused deposition modeling with a quite low cost. Profiting from the fundamental dielectric resonator (DR) mode, the higher order DR mode and the grating mode of the dielectric resonator, the absorber shows an absorptivity higher than 90% over the whole ultra-broad operating band from 3.9 to 12 GHz. The relative bandwidth can reach over 100% and cover the whole C-band (4⁻8 GHz) and X-band (8⁻12 GHz). Utilizing the numerical simulation, we have discussed the working principle of the absorber in detail. What is more, the absorption performance under different incident angles is also simulated, and the results indicate that the absorber exhibits a high absorptivity at a wide angle of incidence. The advantages of low cost, ultra-broad operating band and a wide-angle feature make the absorber promising in the areas of microwave measurement, stealth technology and energy harvesting.

Keywords: 3D printing; Acrylonitrile Butadiene Styrene (ABS), ultra-broadband; Microwave absorption; dielectric resonator; periodical structure.

Figure 1

(a) Prospective view of the element of the absorber. Each part of the element is ranged layer by layer; (b) Side view; and (c) top view of the element. The geometrical parameters are as follows: p = 23.7 mm, d_r = 7.85 mm, h_r = 6.12 mm, h_s = 3.25 mm; (d) Schematic diagram of the whole dielectric-resonator-based ultra-broadband absorber; (e) Design diagram and adopted methodology for the design of the absorber.

Figure 2

(a) Image of the printed cube sample; (b) The experimental setup of the permittivity measurement system; (c) Measured and fitted data of the permittivity of the material.

Figure 3

(a) Simulated absorption spectra of the designed dielectric-resonator-based absorber. The simulated results for the two comparison cases, namely, the dielectric plate with the metal back and the dielectric resonator without the metal back, are also plotted. The four absorption peaks of the designed absorber are marked as f₁, f₂, f₃, and f₄ in the figure; (b) Simulated input impedance of the designed dielectric-resonator-based absorber, with the four absorption peaks marked.

Figure 4

Simulated vector field distribution in the absorber. (a,c,e,g) E-field in xoz plane for f₁, f₂, f₃, and f₄ of 4.41, 6.24, 8.61 and 10.76 GHz, respectively. (b,d,f,h) H-field in yoz plane for f₁, f₂, f₃, and f₄ of 4.41, 6.24, 8.61 and 10.76 GHz, respectively. (i,j,k,l) Power loss density of the resonator in yoz plane for f₁, f₂, f₃, and f₄ of 4.41, 6.24, 8.61 and 10.76 GHz, respectively.

Figure 5

Photo of prototype of the designed absorber. (a) Top side; (b) Bottom side; (c) Simulated and measured absorption spectra of the proposed absorber.

Figure 6

Schematic diagram of oblique-incidence waves for (a) the TE mode and (c) TM mode. Absorption spectra for oblique-incidence waves with different angles of incidence for (b) the TE mode and (d) TM mode.