Effect of Two Different Superstrate Layers On Bismuth Titanate (BiT) Array Antennas

Abstract

The microwave industry has shown increasing interest in electronic ceramic material (ECM) due to its advantages, such as light weight, low cost, low loss, and high dielectric strength. In this paper, simple antennas covered by superstrate layers for 2.30 GHz to 2.50 GHz are proposed. The antennas are compact and have the capability of producing high performance in terms of gain, directivity, and radiation efficiency. Bismuth titanate with high dielectric constant of 21, was utilized as the ECM, while the superstrate layers chosen included a split ring resonator and dielectric material. The superstrate layers were designed for some improvement in the performance of directivity, gain, and return loss. The proposed antennas were simulated and fabricated. The results obtained were small antennas that possess high gain and high directivity with 360°, omni-directional signal transmission that resonant types of conventional dipole antenna cannot achieve. The gain of the antenna with the superstrate layer was enhanced by about 1 dBi over the antenna without a superstrate layer at 2.40 GHz.

Preparation and Characterization of Flexible Substrate Material from Phenyl-Thiophene-2-Carbaldehyde Compound

“…The width, ( w f ) of the microstrip transmission line and the height ( h ) of the microwave substrate have a major correlation with the characteristics impedance along with the effective relative permittivity of the air substrate microstrip system according to the following equation [33]: ${\epsilon }_{eff }\left(f\right)={\epsilon }_r-\frac{{\epsilon }_r-{\epsilon }_{es}}{1+G{\left(\frac{f}{f_d}\right)}^2}$ where the constant: $f_d=\frac{Z_c}{2{\mu }_{0}h}G=0.6+0.0009Z_c$ …”

“…The characteristics impedance [33]: $Z_c\cong \frac{1}{2\pi }\sqrt{\frac{{\mu }_0}{{\epsilon }_{es}{\epsilon }_0}}\log F_{1 }\frac{h}{w}+\sqrt{1+{\left(2\frac{h}{w}\right)}^2}$ where F 1 = 6 + (2 π − 6) exp [−30.666 h / w ]0.7528 and the electrostatic relative permittivity is [33]: ${\epsilon }_{es}\cong \frac{{\epsilon }_{r }+1}{2}+\left(\frac{{\epsilon }_r-1}{2}\right){\left[1+10\left(\frac{h}{w}\right)\right]}^{-\text{ab}}$ where, $\mathrm{normala}=1+\frac{1}{49}\log \left[\frac{{\left(\frac{w}{h}\right)}^2+{\left(\frac{w}{52h}\right)}^2}{{\left(\frac{w}{h}\right)}^4+0.432}\right]+\frac{1}{18.7}\log false[1+{\left(\frac{1}{18.1}\frac{w}{h}\right)}^{3}false]$ and $\mathrm{normalb}=0.564{\left(\frac{{\epsilon }_r-0.9}{{\epsilon }_r+3.0}\right)}^{0.053}$.…”

Gain enhancement of the ultra-wideband tapered slot antenna using broadband gradient refractive index metamaterial

“…The low‐ or zero‐index metamaterial (LIM/ZIM) is a good option for all broadband antennas. Therefore, the research interest among scientists and engineers are exponentially increased on metamaterial based circuits, such as superstrate, artificial magnetic conductor (AMC), and so on, but it provides a limited bandwidth with large losses for electric or magnetic resonant metamaterials. Several works are published in the literature based on these techniques applied in Vivaldi antennas.…”

A new metasurface based on meta‐atom cluster for terahertz applications

“…At the high frequency, it is not possible to ignore the substrate material's effect owing to high loss which is reduced with the utilization of substrate material of very low and thin permittivity. Different shapes of SRRs such as S‐shape resonator, omega resonators, hexagon shape have been mentioned in the literature for meta‐atoms. In the terahertz frequency, researches on double negative meta‐atoms are raised rapidly …”