Design of A Dual Band Metamaterial Absorber for Satellite Communication.

Abstract

Metamaterial absorbers consist of a large number of artificial unit cells and have been intensively researched over the last few decades owing to their low profile, low cost, decreased weight, and required absorption responses, etc. The absorption of electromagnetic frequencies by a metamaterial absorber is contingent on the 120-impedance match between the absorber and vacuum. For microwave use, this research proposes a Metamaterial Absorber (MMA). At both the 29.7 GHz and 31 GHz resonance frequencies, the proposed metamaterial shows absorption of 99.99%. In the ranges of 29.5 GHz to 30.5 GHz and 30.7 GHz to 31.4 GHz, respectively, the 90% absorption bandwidths for these frequencies are 1 GHz and 0.7 GHz. The main mechanism of the dual-band absorption characteristic has been provided, including the absorption, electric field, magnetic field, and surface current distribution. To learn more about the metamaterial's absorption properties, the MMA is evaluated with various polarization angles, and the impact of size is also investigated. By covering a metallic item with metamaterial absorbers, one of their primary roles is to minimize the scattering effects of the metal. With the development of band-notched metamaterial absorbers and hybrid architecture, metamaterial absorbers can now be easily integrated and co-designed with antennas to enhance antenna performance. This thesis also addresses the antenna applications of metamaterial absorbers, from topological analysis to practical implementations. We discuss in detail two antenna configurations on which we worked to reduce dispersion. Using the notch band of a band-notched absorber as the metal ground for an antenna (like a monopole, dipole, or planar patch antenna) is one technique; the antenna can radiate efficiently within the notch band, and the absorbers can absorb incoming electromagnetic waves to significantly reduce scattering effects outside the notch band. In order to build reflect array antennas with minimal scattering effects and gain filtering, the second method equips a unit cell with simultaneous phase-shifting and electromagnetic wave-absorption capabilities. In order to ease the building of reflect array antennas, the phase shift and electromagnetic wave absorption procedures are performed separately. The future of metamaterial absorbers is then evaluated