The project focuses on designing and fabricating models to control the magnitude and frequency of absorbing electromagnetic waves (EMWs) by using metamaterials (Metamaterial Perfect Absorbers - MPAs) operating in the frequency region from 2–18 GHz. Particularly, the magnitude and frequency of absorption of the proposed MPAs will be effectively controlled through the influence of geometrical parameters, metal-dielectric composition, the integration of new materials or through the peripheral impacts. Improve these proposed structures to create controllable MPAs that absorb EMWs in the higher frequency region (THz).

Theoretical results:
- Overview of technologies and new materials, which are suitable for frequency control and absorption magnitude models of variable materials operating in the GHz and THz frequency regions, has been sufficiently evaluated. By exploiting the role of magnetic resonance in a multilayered structure, it was found that the relative-bandwidth of the absorption spectrum, FWB = 27.6% can be switched flexibly from 27.6% to 7.4% (or absorption over 90% to below 80%) in the WiMAX/LTE band by using the truncated cone-type resonators.
- We provide effective solutions to control the frequency and magnitude of absorption of MPAs, which are changed according to the geometrical parameters, the incident angle and the polarization angle of incoming electromagnetic waves in the frequency region of 1–18 GHz.
Applied results: The results of the project solve the problem of controlling the frequency and magnitude of absorption by thermal impacts, which is potential for applications operating in the infrared region.

- Published scientific papers (list):
+ 01 SCI-E international journal: B. X. Khuyen, et al., Narrow/ Broad-Band Absorption Based on Water-Hybrid Metamaterial, Crystals 10, 415 (2020).
+ 02 Prestigious domestic journals:
[1] N.V. Ngoc, et al., “Controlling near-field coupling for switchable metamaterial between absorption and polarization-conversion functions” Vietnam Journal of Science and Technology 2022 (Accepted).
[2] N.V. Ngoc, et al., “A rectangle-quartet metamaterial for dual-band perfect absorption in the visible region,” Communications in Physics, 32(2), 169 (2022).
- Patents (list): N/A.
- Technological products (describe in details: technical characteristics, place): 05 Fabricated MPA samples, whose frequency and magnitude of absorption spectra can be controlled, stored at the Graduate University of Science and Technology.
- Other products (if applicable): 01 Master graduated.