Frequency tunable graphene metamaterial reflectarray for terahertz applications

Zainud-Deen, S.H.; Mabrouk, Ahmed M.; Malhat, Hend A.

doi:10.1049/joe.2018.5016

Cited by 17 publications

(16 citation statements)

References 27 publications

(27 reference statements)

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“…At present, the solid-state sub-millimeter wave and terahertz technologies, such as frequency multiplication, detection, mixing, power amplification and combiner based on various types of diodes and transistors [1]- [6], are moving toward higher operating frequency bands, higher output power and newer materials [7], [8]. Due to the lack of high power and stable radiation sources operating at higher frequency, the mixing technology has received rising popularity for the design of sub-millimeter wave or terahertz system.…”

Section: Introductionmentioning

confidence: 99%

A 200–240 GHz Sub-Harmonic Mixer Based on Half-Subdivision and Half-Global Design Method

Cui

Zhang

et al. 2020

IEEE Access

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For the terahertz harmonic mixer, a design model based on Half-Subdivision and Half-Global Design Method (HS-HGDM) with a single functional unit is proposed. The single functional unit circuit of the mixer, such as LO or IF Low Pass Filter (LPF), is designed by Subdivision Design Method (SDM), and the rest circuits of the mixer are designed by Global Design Method (GDM). The harmonic mixer based on this model is characterized by simple circuit structure, low conversion loss, small circuit size and high stability. In this paper, an improved Compact Suspended Micro-strip Resonators (CSMRs) filter is developed for the IF part of sub-harmonic mixer. The remaining circuits consist of some basic transmission units, such as the High-Z Low-Z impedance Transmission Lines (H-Z L-Z TLs) applied for main circuit, and full/reduced height WR4.3/WR8 applied for providing RF/LO signal. In RF frequency range 200-240 GHz, a Single Sideband (SSB) conversion loss of 7.36±0.76 dB operating at IF frequency 1.8 GHz, and a Double Sideband (DSB) noise temperature below 1034 K with the LO power of 2-5 mW and the LO frequency of 107 GHz were achieved. This broadband sub-harmonic mixer operates at room temperature, which makes it applicable to sub-millimeter wave or terahertz wireless communication systems and imaging inspection systems. INDEX TERMS Terahertz sub-harmonic mixer, CSMRs filter, wireless communication systems.

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Section: Introductionmentioning

confidence: 99%

A 200–240 GHz Sub-Harmonic Mixer Based on Half-Subdivision and Half-Global Design Method

Cui

Zhang

et al. 2020

IEEE Access

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“…The atomically-thick graphene can be modulated as an impedance surface with frequency dependent complex conductivity [42] which has both intraband and interband contributions [36], i.e. σ g (ω, µ c , Γ, T ) = σ +jσ = σ intra +σ inter .…”

Section: Graphene Patch Modeling a Graphene Conductivitymentioning

confidence: 99%

Graphene Based Tunable Terahertz Holographic Antennas

Ren

Jiang

2022

IEEE Open J. Antennas Propag.

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In this work, several representative terahertz (THz) graphene holographic impedance surface antenna are presented. Different to the conventional impedance surface antenna that manipulates the surface impedance via varying the patch size in each unit cell, the surface impedance of the proposed antenna in this paper is readily controlled by applying a tunable DC biasing to each graphene patch cell, the physics behind which is that the conductivity of the graphene is a function of imposed voltage. Thus, the graphene patches of the proposed antenna have same size as well as equal spacing, which makes the modeling process more convenient and efficient. Furthermore, for the purpose of beam scanning, the proposed THz graphene holographic antenna can be easily reached by varying the DC supply. Besides, due to the excellent mechanical property of graphene, the proposed THz graphene holographic antenna can be designed conformal to required platforms. To validate and verify the proposed above ideas, a linear polarized with beam scanning capability, a circularized and a conformal THz graphene holographic antenna are designed and simulated via full-wave commercial software HFSS, the simulation results are in good agreements with the design theories. Graphene, holographic antenna, reconfigurability, terahertz (THz) INDEX TERMS

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“…The operating frequency of the MM surfaces can be tuned geometrically by changing the dimensions of one/all constituent parts of the unit-cell element that result in changing its conductance and capacitance [25]. The performance of the MM unit-cell elements can be changed electrically, thermally, chemically, or optically according to the type of materials used in the proposed design [26]. It can also be changed using positive intrinsic negative (PIN) diodes, varactor diodes, or microelectromechanical systems (MEMS) [27].…”

Section: Introductionmentioning

confidence: 99%

Reconfigurable Graphene-Based Metamaterial Polarization Converter for Terahertz Applications

Mabrouk

Donkol

Seliem

2022

Preprint

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This paper suggests a high gain polarization converter using a graphene-based metamaterial array. The graphene-based metamaterial polarization converter is a rectangular array that consists of 20 periodic unit-cell elements. Each graphene-based metamaterial unit-cell element consists of a rectangular patch with four triangular-shaped graphene parts at its four corners. The rectangular patch with the four graphene parts are placed over a rectangular substrate backed with a perfect electric conductor (PEC) and has a relative permittivity of εsub = 3.38. The metamaterial characteristics of the proposed graphene-based metamaterial unit-cell element are obtained over a wide range of frequencies of 0.7 THz ranging from 1.5 THz to 2.2 THz. The graphene-based metamaterial array is placed over a linear polarized slot antenna that operates at 1.8 THz with a maximum gain of 5.5 dBi. The linearly polarized wave that radiated from the slot antenna can be converted into a reconfigurable right-handed circular polarization (RHCP) or Left-handed circular polarization (LHCP) according to the biasing states of the graphene parts. Moreover, the operating -10 dB B.W of the slot antenna is increased to 22.2%, and the gain is enhanced to 8 dBi at the same operating frequency. A reconfigurable polarization conversion for the slot antenna can be obtained over a wide 3dB axial ratio (AR) B.W from 1.75 THz to 1.92 THz (20% 3dB B. W).

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Frequency tunable graphene metamaterial reflectarray for terahertz applications

Cited by 17 publications

References 27 publications

A 200–240 GHz Sub-Harmonic Mixer Based on Half-Subdivision and Half-Global Design Method

A 200–240 GHz Sub-Harmonic Mixer Based on Half-Subdivision and Half-Global Design Method

Graphene Based Tunable Terahertz Holographic Antennas

Reconfigurable Graphene-Based Metamaterial Polarization Converter for Terahertz Applications

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