To meet the demand for modern communication technology, the development of satellite communications has been consistently investigated. In this article, a rectangle-type SRR is attached to circular-type SRR for obtaining two frequencies in X-band operation. The designed structure exhibits negative metamaterial properties (Epsilon, mu and refractive index are negative) and the design was fabricated on a polyimide dielectric material with a 10 × 10 mm2 size. The polyimide dielectric material is chosen with a thickness of 0.1 mm and a dielectric constant of 0.0027. The proposed unit cell is designed and simulated by using one of the numerical simulation tools, CSTMW studio, in which the frequency limit is chosen from 7 to 12 GHz. From the results, we can observe that the proposed design resonates at two X-band frequencies at 9.84 GHz and 11.46 GHz and the measurement results of the proposed design resonate at 9.81 GHz and 11.61 GHz. It is worth noting that the simulation and measurement findings both obtain the same X-band frequencies, with only a minor difference in the frequency values. Thus, the recommended design is very much useful for X-band applications.

In this research article, we proposed a split ring resonator(SRR) based metasurface absorber based on graphene material. The performance of the graphene-based absorber at terahertz frequencies can be altered by varying the chemical potential of graphene material. Because of its excellent tunability and optical responsiveness at terahertz frequency, graphene-based metamaterials have been widely used in optoelectronic devices, sensors, filters, and many more. The proposed structure contains three layers namely graphene-based patch a conductive layer, lossy silicon as a dielectric layer, and finally gold as a bottom conductive layer. The purpose of this research is to present a thorough investigation of graphene-based THz metamaterial absorbers, including modeling and verification of the structure through an equivalent circuit approach. It is very much beneficial to understand the conductive phenomenon of graphene material by tuning the fermi chemical potential.

Terahertz era is becoming a more prominent and expanding platform for a variety of applications. In this paper, we propose a triband absorber with a hexagon-shaped radiating patch for THz applications. The proposed structure has three layers: a hexagonal patch made of graphene as a radiating patch, a silicon layer as a dielectric substrate, and a bottom conductive layer made of gold to prevent EM wave transmission. The proposed structure operates at three resonant frequencies 0.38 THz, 1.23 THz, and 1.77 THz, respectively. We may accomplish maximum absorption level (above 90%) and maximum absorption bandwidth by setting relevant chemical potential and relaxation times to 0.2 ev and 0.2 ps, respectively. The proposed structure contains a lossy silicon substrate, which has a dielectric constant of 11.9 and a loss tangent of 2.5e−004. The proposed structure is experimented with three layers, and the effect on absorbance for different modes is illustrated.

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In this research article, a novel MBBA nematic liquid crystal (NLC) based circular trident-shaped antenna is proposed for both C-band and X-band microwave applications. The proposed antenna contains a trident-shaped radiating patch, which is made of copper material, and glass material is utilized as a dielectric substrate for the proposed novel MBBA-based trident shaped antenna. The dielectric substrate contains two glass plates with a thickness of 1 mm each and is separated by an air gap of 0.003 mm to fill MBBA nematic liquid crystal. So, the overall size of the proposed antenna will become 15 × 20 × 2.003 mm3. The dielectric constant of each glass plate is chosen as 5.438. However, the antenna operates at a single frequency band, when MBBA material is not present between the glass plates and produces two distinct resonant frequencies when the air gap between the glass plates is filled with MBBA NLC. Antenna radiation parameters such as gain, radiation efficiency, reflection coefficient, and radiation patterns are compared for both simulation and measurement.