Circularly polarized graphene based transmitarray for terahertz applications

Malhat, Hend A.; Gaber, Shaymaa M.

doi:10.1109/ursigass.2014.6929189

Cited by 8 publications

(7 citation statements)

References 10 publications

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“…Finally, only normal incidence is considered. However, the plane wave has an oblique angle on the real array element, but the phase variation is nearly the same for incidence angles up to 30 o [14]. Different metals are used for ground plane as silver, gold, copper, and aluminum.…”

Section: Design Of Ndra Reflectarray Antennamentioning

confidence: 99%

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Nano-Dielectric Resonator Antenna Reflectarray/Transmittarray for Terahertz Applications

Malhat¹,

Eltresy²,

Zainud-Deen³

et al. 2015

AEM

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Nanoantennas have been introduced for different applications as solar-cell, medical imaging, and fast data communications. The material properties of good conducting metals introduce plasmonic behavior at terahertz frequencies. The electrical properties of different good conducting metals are modelled using the Drude model and have been investigated for reflectarray/ transmitarray operation. The radiation characteristics of nano-dielectric resonator antenna (NDRA) reflectarray at 633 nm have been investigated. The unit-cell consists of NDR mounted on the metallic supporting plane. A parametric study for the NDR unit cell dimensions and material has been introduced. The NDR unit-cell with silver supporting plane has been designed and analyzed for reflectarray applications at 633 nm. The radiation characteristics of the NDRA transmitarray has been introduced for 633 nm applications. The NDR unit-cell consists of two NDRs mounted on the top and bottom of the metallic supporting plane. A comparison between the radiation characteristics of 17×17 and 21×21 NDRA transmitarray has been introduced. A compromise between the nano-transmitarray size, maximum gain, and operating bandwidth is applied to terahertz applications. The finite integral technique is used to carry a full wave analysis to design an NDRA reflectarray and an NDRA transmitarray..

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Section: Design Of Ndra Reflectarray Antennamentioning

confidence: 99%

“…A detailed analysis of the radiation characteristics of nano-dielectric resonator antenna single element and the NDRA reflectarray at 633 nm is investigated in [10]. A circularly polarized graphene transmitarray for terahertz application has been presented in [14].…”

Section: Introductionmentioning

confidence: 99%

Nano-Dielectric Resonator Antenna Reflectarray/Transmittarray for Terahertz Applications

Malhat¹,

Eltresy²,

Zainud-Deen³

et al. 2015

AEM

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“…The X is a constriction factor, which is used, alternatively to w to limit the velocity. A detailed discussion of the particle swarm optimizer used in this paperis provided in [17].The optimization is performed to minimize the square norm F F = I��l [(ReF/TCfn) -RePSOCfn)) 2 + (ImF/TCfn) -ImPSOCfn)) 2 ] (7) where Nf is the number of frequency points, Re FIT (f,, ) and 1m FIT (f,, ) are the real and imaginary parts of the input impedance calculated using the FIT. Re Ps0 (f,, ) and 1m Ps0 (f,, ) are the real and imaginary parts of the input impedance calculated using the equivalent circuit model with its components are optimized by PSO.…”

Section: B Particle Swarm Optimizationmentioning

confidence: 99%

“…The PSO is used to estimate the coefficients of the rational function for minimization of square norm F given by Eq. (7). The rational function representing the input impedance dependence on frequency can be expressed as [21], (8) where a,andb; (i=0,1, .. ,4 ) are unknown coefficients ands = jw.…”

Section: Five-element Equivalent Circuitmentioning

confidence: 99%

“…It supports surface plasmon polaritons in the THz range that are widely tunable by a change of graphene's electrochemical potential via chemical doping, or magnetic field or electrostatic gating. Because of its unique characteristics, graphene is envisaged to enable new potential applications, ranging from ultra high-speed transistors to transparent solar cells [7]. Graphene is a promising material for the realization of miniaturized resonant THz antennas [8].…”

Section: Introductionmentioning

confidence: 99%

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B9. Equivalent circuit with frequency-independent lumped elements for plasmonic graphene patch antenna using particle swarm optimization technique

Malhat

2015

2015 32nd National Radio Science Conference (NRSC)

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Graphene patch microstrip antenna has been investigated for 600 GHz applications. The graphene material introduces a reconfigurable surface conductivity in terahertz frequency band. The input impedance is calculated using the finite integral technique. A five-lumped elements equivalent circuit for graphene patch microstrip antenna has been investigated. The values of the lumped elements equivalent circuit are optimized using the particle swarm optimization techniques. The optimization is performed to minimize the mean square error between the input impedance of the fmite integral technique and that calculated by the equivalent circuit model. The effect of varying the graphene material chemical potential and relaxation time on the radiation characteristics of the graphene patch microstrip antenna has been investigated. An improved new equivalent circuit model has been introduced to best fitting the input impedance using a rational function and PSO. The Cauer's realization method is used to synthesize a new lumped-elements equivalent circuits.

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Advances in Transmitarray Antennas

Feng

Xiao

2020

Wiley Encyclopedia of Electrical and Electronics Engineering

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Recent advances in the art of transmitarray antenna (TAA) designs are summarized in this article, mainly focusing on the TAA element designs, improved feeding mechanisms, methods of designing wideband and ultra‐wideband TAAs, and TAAs for beam‐steering applications. Firstly, according to the diverse‐phase shifting mechanisms, representative TAA elements in the available literatures are categorized into four groups, including the receiving–transmitting elements, multilayer frequency‐selective surface‐type elements, polarization‐conversion elements, and phase‐rotation elements. Based on their own specific properties, designers can flexibly select the proper elements for different application scenarios. Moreover, primarily aiming at reducing the overall profile, some improved feeding mechanisms are discussed, for example, the folded TAA, TAA with the feeds of the multihorn configuration, the auxiliary small TAA, the integrated leaky‐wave antenna, the Cassegrain reflectarray, or a small‐scale array antenna. Subsequently, numerous typical solutions to improve the inherently narrow bandwidths of the TAAs are also presented. It can be concluded that the wideband performances of the non‐true‐time‐delay TAA are realized by optimizing the element‐phase errors and transmission losses at all designing frequencies. If the true‐time‐delay elements are employed, the key point is utilizing their group delays to appropriately compensate the spatial phase delays. Finally, for highly demanded beam‐steering applications, the TAAs incorporated with the techniques of reconfigurable, mechanical scan, switched beam, or phased array antenna (PAA) feed are introduced. Specifically, representative designs of the PAA‐fed TAAs are presented in detail, which will be a promising technical candidate of high‐gain beam scanning antennas.

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Circularly polarized graphene based transmitarray for terahertz applications

Cited by 8 publications

References 10 publications

Nano-Dielectric Resonator Antenna Reflectarray/Transmittarray for Terahertz Applications

Nano-Dielectric Resonator Antenna Reflectarray/Transmittarray for Terahertz Applications

B9. Equivalent circuit with frequency-independent lumped elements for plasmonic graphene patch antenna using particle swarm optimization technique

Advances in Transmitarray Antennas

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