scholarly journals Dual-Frequency Polarized Reconfigurable Terahertz Antenna Based on Graphene Metasurface and TOPAS

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1088
Author(s):  
Jinnan Zhang ◽  
Shijie Tao ◽  
Xin Yan ◽  
Xia Zhang ◽  
Jinxuan Guo ◽  
...  
Keyword(s):  
Chemical Potential ◽  
Polarization State ◽  
Dielectric Substrate ◽  
Hybrid Structure ◽  
Substrate Material ◽  
Multilayer Graphene ◽  
Polarization Conversion ◽  
Dual Frequency ◽  
Terahertz Antenna ◽  
Linearly Polarized

A hybrid dual-frequency polarized reconfigurable terahertz antenna is designed and studied. Graphene and TOPAS are employed as the polarization conversion metasurface and dielectric substrate, respectively, enabling tunable polarization conversion and circular polarization. TOPAS is a good substrate material for broadband THz components due to its low absorption. By adjusting the chemical potential of graphene between 0 eV and 0.5 eV, the polarization state in the band of 1 THz (0.76–1.02 THz) and 2.5 THz (2.43–2.6 THz) can be reconstructed. Thanks to the multilayer graphene structure and low absorption TOPAS, the graphene metasurface exhibits a broad bandwidth of 0.26 and 0.17 THz, respectively, in the band of 1 THz and 2.5 THz. The working state of the circularly polarized antenna and linearly polarized antenna can be switched in the bands around 1 THz (0.7–0.75 THz, 0.96–1.04 THz) and 2.5 THz (2.42–2.52 THz), respectively, without changing the physical geometry. Moreover, the graphene antenna, metasurface, and hybrid structure are tested, respectively, to verify that the components do not interfere with each other in performance. The hybrid antenna shows great potential in tunable terahertz devices and related applications.

scholarly journals Effects of dielectric substrate material microstrip antenna for limited band applications

2021 ◽  
Vol 2070 (1) ◽  
pp. 012124
Author(s):  
Ravi Shankar Saxena ◽  
S Kavitha ◽  
Ashish Singh ◽  
Anurag Mishra
Keyword(s):  
Radiation Pattern ◽  
Patch Antenna ◽  
Microstrip Antenna ◽  
Dielectric Substrate ◽  
Substrate Material ◽  
Microstrip Patch Antenna ◽  
Simulation Software ◽  
Dielectric Constants ◽  
Dual Frequency ◽  
Microstrip Patch

Abstract In this paper, an analysis of dual frequency resonance antenna is achieved by OM-shape microstrip patch antenna. The proposed antenna is analyzed using IE3D simulation software. The analysis of proposed structure is done by varying the dielectric constants and height of the substrate as well as gain and radiation pattern of the antenna is obtained. It observed that on varying the dielectric substrate the effect on proposed antenna is very effective.

scholarly journals Tunable Coupled-Resonator-Induced Transparency in a Photonic Crystal System Based on a Multilayer-Insulator Graphene Stack

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2042 ◽  
Author(s):  
Hanqing Liu ◽  
Jianfeng Tan ◽  
Peiguo Liu ◽  
Li-an Bian ◽  
Song Zha
Keyword(s):  
Photonic Crystal ◽  
Optical Sensors ◽  
Chemical Potential ◽  
Structural Parameters ◽  
Multilayer Graphene ◽  
Crystal System ◽  
Chemical Potentials ◽  
Nonlinear Devices ◽  
Induced Transparency ◽  
Coupled Resonator

We achieve the effective modulation of coupled-resonator-induced transparency (CRIT) in a photonic crystal system which consists of photonic crystal waveguide (PCW), defect cavities, and a multilayer graphene-insulator stack (MGIS). Simulation results show that the wavelength of transparency window can be effectively tuned through varying the chemical potential of graphene in MGIS. The peak value of the CRIT effect is closely related to the structural parameters of our proposed system. Tunable Multipeak CRIT is also realized in the four-resonator-coupled photonic crystal system by modulating the chemical potentials of MGISs in different cavity units. This system paves a novel way toward multichannel-selective filters, optical sensors, and nonlinear devices.

scholarly journals Formation of Fractal Antenna Array for Multiband Applications

2019 ◽  
Vol 8 (4) ◽  
pp. 3257-3263
Keyword(s):  
Wireless Communication ◽  
Antenna Array ◽  
Microstrip Antenna ◽  
Dielectric Substrate ◽  
High Gain ◽  
Substrate Material ◽  
Vital Role ◽  
Fractal Antenna ◽  
Self Similarity ◽  
Wireless Applications

Antennas play a vital role in wireless communication; a thirst of excellence in this area is unending. Proposed work describes a concept of fractal multiband antenna designed in the hexagon shape. Basically fractal is the concept used in Microstrip antenna for giving better results than conventional Microstrip antenna. By using hexagonal fractal antenna we can possibly achieve the radiation pattern with high gain. The coaxial feeding is used and multiple hexagons are interconnected in array for maintaining conductivity and to preserve electrical self similarity. Hexagonal antenna is used for different wireless applications. The proposed antenna frequency band covers a large number of wireless communication applications including GPS (1.6GHz), Bluetooth (2.4 GHz) & WLAN (3.6GHz). Antenna design has been designed and simulated by using the software Ansoft’s HFSS and parameters like bandwidth return loss, directivity, VSWR are analyzed. Fabrication of the antenna is done by using wet-etching method, on FR-4 dielectric substrate material. Experimental results are taken on Vector Network Analyzer (VNA) and those obtained results were compared with simulated results. The hexagonal fractal antenna array is found to possess predictable multiband characteristics.

Characterization of Ultra-Thin Epoxy-Resin Based Dielectric Substrate for Flexible Power Electronics Applications

2017 ◽  
Vol 2017 (1) ◽  
pp. 000151-000156 ◽  
Author(s):  
Xin Zhao ◽  
K. Jagannadham ◽  
Wuttichai Reainthippayasakul ◽  
Michael T. Lanagan ◽  
Douglas C. Hopkins
Keyword(s):  
Thermal Conductivity ◽  
Epoxy Resin ◽  
Power Electronics ◽  
Flexible Electronics ◽  
Dielectric Material ◽  
Dielectric Substrate ◽  
Substrate Material ◽  
Superior Performance ◽  
Wearable Electronics ◽  
Power Module

Abstract Available substrate materials for power module applications has been investigated for a long time. Though Direct Bonded Copper (DBC) substrates, nowadays, have been widely applied in power electronics applications, especially power modules, due to its superior performance in mechanical ruggedness, thermal conductivity, and isolation capability. Its cost and complicated requirements during fabrication processes are always concerns in industries. At the same time, flexible electronics has become a rapidly expanding area with commercial applications including displays, medical, automotive, sensors arrays, wearable electronics, etc. This paper will initiate an investigation on a dielectric material that has potential in high power wearable electronics applications. A recently developed ultra-thin Epoxy-Resin Based Dielectric (ERBD) substrate material which is suitable for power electronic applications, is introduced. The ERBD can be fabricated with thickness as low as 80μm, with more than 5kV DC isolation capability. Its thermal conductivity is 8W/mK, higher than similar product currently available in the market. ERBD is also able to be bonded with Cu plates on both sides. In this paper, the properties of ERBD are investigated. Scanning Electron Microscope (SEM) is applied to analyze the microstructure of ERBD, and its bonding interface with Cu plates. 3-omega and Transient Thermal Reflectance methods are employed to precisely measure the thermal conductivity. Dielectric constant and loss are measured at different frequency. Simulations are applied to correct the error from the fringing effect during the measurement. The leakage current of ERBD is also measured under different voltage and temperature with DC and AC condition. Reliability tests are conducted to examine the electrical isolation and shearing strength of ERBD. The suitability of ERBD for potential flexible power electronics application is discussed based on the results from investigation of properties of the dielectric.

A dynamically tunable and wide-angle terahertz absorber based on graphene-dielectric grating

2020 ◽  
Vol 34 (27) ◽  
pp. 2050292
Author(s):  
Chunyan Wu ◽  
Yiqiang Fang ◽  
Linbao Luo ◽  
Kai Guo ◽  
Zhongyi Guo
Keyword(s):  
Chemical Potential ◽  
Incident Angle ◽  
Near Field ◽  
Absorption Efficiency ◽  
Multilayer Graphene ◽  
Wide Angle ◽  
Terahertz Absorber ◽  
Tunable Range ◽  
Magnetic Components ◽  
Dielectric Grating

We theoretically and numerically demonstrate a tunable and wide-angle terahertz absorber, which is composed of multilayer graphene-dielectric grating and bottom metal substrate. Numerical simulation shows that the proposed absorber has the advantage of dynamically tunable range from 1.015 THz to 1.165 THz when the chemical potential of graphene increases from 10 meV to 150 meV. The absorption efficiency can reach a high value of 99%. To show the working mechanism of absorption, the near field distributions of magnetic components are presented at the absorption wavelength. We also demonstrate that the tunable range of absorption can be engineered by designing the geometry parameters. In addition, it is shown that the designed absorber can maintain the good performance of absorption over a wide incident angle from [Formula: see text] to [Formula: see text] under TM-polarization.

Plasmon spectrum of graphene monolayer on substrate

2019 ◽  
Vol 33 (09) ◽  
pp. 1950102
Author(s):  
I. N. Askerzade ◽  
R. T. Askerbeyli
Keyword(s):  
Substrate Material ◽  
Plasmon Mode ◽  
Monolayer Graphene ◽  
Graphene Monolayer ◽  
Multilayer Graphene ◽  
Linear Dispersion ◽  
Long Wavelength ◽  
Theoretical Considerations ◽  
Plasmon Spectrum ◽  
Good Agreement

Plasmon modes in monolayer graphene on substrate are analyzed taking into account the thickness of graphene and substrate material layer in the evaluation of Coulomb potential. It is shown that plasmon mode in graphene monolayer has linear dispersion in contrast to multilayer graphene in long-wavelength limit. The slope of plasmon spectrum is determined by the thickness and dielectric constant of substrate. Obtained results are in good agreement with experimental data and other theoretical considerations.

scholarly journals Dual-band dichroic asymmetric transmission of linearly polarized waves in terahertz chiral metamaterial

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3235-3242 ◽  
Author(s):  
Tingting Lv ◽  
Xieyu Chen ◽  
Guohua Dong ◽  
Meng Liu ◽  
Dongming Liu ◽  
...  
Keyword(s):  
High Performance ◽  
Light Propagation ◽  
Polarization State ◽  
Dual Band ◽  
Terahertz Waves ◽  
Asymmetric Transmission ◽  
Polarized Waves ◽  
Wide Range ◽  
Linearly Polarized ◽  
Chiral Metamaterial

AbstractPolarization conversion dichroism is of particular interest in manipulating the polarization state of light, whereas high-performance asymmetric transmission (AT) of linearly polarized waves is still inaccessible in the terahertz range. Here, a bilayer chiral metamaterial consisting of orthogonally chained S-shaped patterns with broken symmetry along the light propagation direction is proposed and demonstrated experimentally to realize a dual-band dichroic AT effect for linearly polarized terahertz waves. The AT effects are robust across a wide range of incident angles. The observed strong AT can be theoretically explained by a multiple reflection and transmission interference model and the transfer matrix method. The proposed bilayer chiral metamaterial may have broad applications in polarization manipulation, chiral biosensing and direction-dependent information processing.

scholarly journals Design and Validation of an Antipodal Vivaldi Antenna with Additional Slots

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Marek Dvorsky ◽  
Harihara S. Ganesh ◽  
S. Sadhish Prabhu
Keyword(s):  
Linear Polarization ◽  
Dielectric Substrate ◽  
Substrate Material ◽  
Radiation Efficiency ◽  
Operating Frequency ◽  
Frequency Range ◽  
High Radiation ◽  
Maximum Gain ◽  
Operating Frequency Range ◽  
Vivaldi Antenna

This paper introduces an improved shape of Antipodal Vivaldi Antenna from the normal schematic structure which yields a high radiation gain. We have designed and fabricated the improved structure of Antipodal Vivaldi Antenna with the help of new dielectric substrate ASTRA®MT77 material. We have chosen a unique substrate material to develop our novel Antipodal Vivaldi Antenna because most research has been done on commonly used materials like FR4, RT Duroid, etc. Moreover, ISOLA has significantly good electrical and nonelectrical properties as compared with other substrate materials. The results of the desired antenna were simulated through extensive simulations performed in CST Microwave Studio®. The characteristics of all the antenna parameters are clearly studied and we are successful to achieve closed results between designed as well as experimented Vivaldi Antenna. The simulated antenna achieved a maximum gain of more than 9 dBi whereas the experimental antenna reached around 7 dBi between the operating frequency range from 1 GHz to 13 GHz. The measured prototype antenna provides linear polarization with overall radiation efficiency of more than 90%.

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