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• Compact Tunable negative Metamaterial for enhancing 5G network performance. • Frequency-Tunable Tri-Hexagon and Tri-Square Split Ring Resonator for Bandwidth Optimization. • Empowering 5G with Double Negative (DNG) Properties. • Fabrication of the proposed metamaterial experimental result to verify the overall performance. This paper introduces a compact tuneable metamaterial (MTM) unit cell featuring a tri-hexagon and tri-square split ring resonator (THTSSSR) structure designed for 5G communication applications. Metamaterials are employed to achieve unique electromagnetic properties not found in natural materials. The design process involves the arrangement of three square rings and three hexagon rings as metallic patches on a Rogers substrate (RT 5880), measuring 7 x 7 mm2 with a thickness of 1.575 mm. The proposed design exhibits double negative (DNG) properties, with resonances in the transmission coefficient (S21) at 3.493 GHz and a bandwidth of −10 dB covering frequencies between 3.057 and 3.711 GHz. Numerical simulations conducted using finite-integration techniques (FIT) in CST Microwave Studio validate the design's effectiveness, with confirmation through the Advanced Design System (ADS). The MTM unit cell demonstrates tuneable attributes, including negative permittivity ranging from 3.39 to 5 GHz and negative permeability from 3.39 to 3.86 GHz. These findings highlight the compactness and tunability of the proposed design, making it promising for 5G communication applications. [ABSTRACT FROM AUTHOR]

Abstract: A kind of planar left-handed metamaterial (LHM) with unique configurations is demonstrated, which offers an approach in building dual-band negative-index materials. Simulated and experimental results predict two left-handed transmission bands near 11.1 and 14.6GHz. Dual bands of negative refractive indexes are verified using the retrieval procedure. Field and current distribution at the dual magnetic resonance are also examined. The effective electromagnetic parameters show that by carefully adjusting dimensions of the unit cell, electric and magnetic resonances can be coexistent at some frequency ranges with both negative permittivity and negative permeability. The idea can help us designing planar negative-index materials with multibands. [ABSTRACT FROM AUTHOR]

Abstract: Based upon Landau–Lifshitz equation and Maxwell''s equations, we theoretically investigated properties of normally incident microwave propagation in interlayer exchange-coupled trilayer ferromagnetic film. It is found that, near resonance frequency of optic mode, imaginary part of permeability of one ferromagnetic layer is smaller than zero unusually, i.e., the ferromagnetic layer may be taken as an active medium. Thus a number of unique electromagnetic properties are presented, such as, the ferromagnetic layer becomes a left-handed material near low side of the resonance frequency of optic mode, and both phase velocity and time-averaged Poynting flow of the usually defined forward wave are negative simultaneously near high side of the resonance frequency. This work provides a feasible active medium to demonstrate the unique microwave properties. [Copyright &y& Elsevier]

Abstract: As a possible candidate for the left-handed metamaterial with negative permeability, a series of Ti, Co-substituted M-type barium hexaferrite BaFe12− x (Ti0.5Co0.5) x O19 (x=0, 1, 2, 3, 4 and 5) was prepared by citrate precursor method. The formation processes of the substituted barium hexaferrite compounds from the precursors were followed by the measurements of powder X-ray diffraction (XRD), Infrared absorption spectra (FT-IR), and thermogravimetry and differential thermal analysis (TG/DTA) coupled with mass spectroscopy (MS). In the case of the non-substituted sample, the formation of the barium hexaferrite is regulated by the thermal decomposition of BaCO3 and the solid-state reactions of BaO and Fe2O3 in the temperature range from 800 to 1100K. The formation temperature of the substituted BaFe12− x (Ti0.5Co0.5) x O19 is higher than that for the non-substituted sample and increases with the value of x, due to the effects of carbonate ions incorporated by the partial substitution of Fe3+ by (Ti0.5Co0.5)3+. On heating up to ca. 1200K, all the substituted samples transform into the magenetoplumbite phase as is the non-substituted sample. The compositional dependence of the magnetic properties of the substituted barium hexaferrite was investigated by the magnetization measurement. The decrease in the magnetic anisotropy was confirmed by the change in the magnetization curve and coercivity H C with the composition x. A negative permeability spectrum was observed in the BaFe9(Ti0.5Co0.5)3O19 in the frequency range from 2 to 4GHz. [Copyright &y& Elsevier]

Abstract: On the basis of Landau–Lifshitz–Gilbert (LLG) equation, an anomalous ferromagnetic resonance behavior is demonstrated in detail. Coupling between the magnetic moments produces a 3π/2 phase delay for one of the moments ferromagnetic resonance unusually, thus leads the sign of magnetic susceptibility to be opposite to that induced by the usual ferromagnetic resonance. Consequently, a left-handed material (LHM) may be formed near the low-frequency side of the resonance. Particularly, a LHM with negative value of real part of permeability only is predicted. [Copyright &y& Elsevier]

Abstract: We investigate the possibility of preparing left-handed material in a layered alternated nonmagnetic/magnetic composite under different direction of incident electromagnetic wave at the microwave region. We calculate the effective refractive index of the layered composites and find that the effective refractive index varies as a function of the volume fraction of one component of the composite. Especially, within the certain volume fraction of component 1 (or 2) the effective refractive index can be negative at a finite frequency region. Moreover, we find that the direction of the incident electromagnetic wave affects the effective refractive index greatly. When the incident electric field is parallel to the laminations and the magnetic field is perpendicular to the laminations, the volume fraction of component 1 (or 2) range, which causes the effective refractive index to be negative, is relatively wider than that of the opposite case, but the absolute values of the negative refractive index are smaller than that of the opposite case. [Copyright &y& Elsevier]