Band Gap Mechanism and Design of a New Type of Six-Ligament Chiral Structure

2021 ◽  
Author(s):  
Yajun Xin ◽  
Ran Wang ◽  
Yongtao Sun ◽  
Qian Ding ◽  
Shuliang Cheng
Keyword(s):  
Band Gap ◽  
Chiral Structure ◽  
New Type

Germanene/GaGeTe heterostructure: a promising electric-field induced data storage device with high carrier mobility

2020 ◽  
Vol 22 (9) ◽  
pp. 5163-5169 ◽  
Author(s):  
Fu-Bao Zheng ◽  
Liang Zhang ◽  
Jin Zhang ◽  
Pei-ji Wang ◽  
Chang-Wen Zhang
Keyword(s):  
Electric Field ◽  
Band Gap ◽  
Data Storage ◽  
Carrier Mobility ◽  
Electronic Devices ◽  
Storage Device ◽  
New Type ◽  
High Carrier Mobility ◽  
High Carrier ◽  
Opening Up

Opening up a band gap without lowering high carrier mobility in germanene and finding suitable substrate materials to form van der Waals heterostructures have recently emerged as an intriguing way of designing a new type of electronic devices.

Square microstrip multi band fractal antenna using EBG structure for wireless applications

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Suresh Akkole ◽  
Vasudevan N.
Keyword(s):  
Band Gap ◽  
Frequency Band ◽  
Microstrip Antenna ◽  
Return Loss ◽  
Dielectric Materials ◽  
Fractal Antenna ◽  
Electromagnetic Band Gap ◽  
Content Type ◽  
New Type ◽  
Multi Band

Purpose Application of electromagnetic band gap (EBG) i.e. electromagnetic band gap technique and its use in the design of microstrip antenna and MIC i.e. microwave integrated circuits is becoming more attractive. This paper aims to propose a new type of EBG fractal square patch microstrip multi band fractal antenna structures that are designed and developed. Their performance parameters with and without EBG structures are investigated and minutely compared with respect to the resonance frequency, return loss, a gain of the antenna and voltage standing wave ratio. Design/methodology/approach The fractal antenna geometries are designed from the fundamental square patch and then EBG structures are introduced. The antenna geometry is optimized using IE3D simulation tool and fabricated on low cost glass epoxy FR4, with 1.6 mm height and dielectric materials constant of 4.4. The prototype is examined by means of the vector network analyzer and antenna patterns are tested on the anechoic chamber. Findings Combining the square fractal patch antenna with an application of EBG techniques, the gain of microstrip antenna has been risen up and attained good return loss as compared to the antennas without EBG structures. The designs exhibit multi-frequency band characteristics extending in between 1.70 and 7.40 GHz. Also, a decrease in antenna size of 34.84 and 59.02 per cent for the first and second iteration, respectively, is achieved for the antenna second and third without EBG. The experimental results agree with that of simulated values. The presented microstrip antenna finds uses in industrial, scientific and medical (ISM) band, Wi-Fi and C band. This antenna can also be used for satellite and radio detection and range devices for communication purposes. Originality/value A new type of EBG fractal square patch microstrip antenna structures are designed, developed and compared with and without EBG. Because of the application of EBG techniques, the gain of microstrip antenna has been risen up and attained good return loss as compared to the antennas without EBG structures. The designs exhibit multi-frequency band characteristics extending in between 1.70 and 7.40 GHz, which are useful for Wi-Fi, ISM and C band wireless communication.

scholarly journals Colloidal photonic crystal cladded optical fibers: Towards a new type of photonic band gap fiber

2005 ◽  
Vol 13 (17) ◽  
pp. 6454 ◽  
Author(s):  
Jianzhao Li ◽  
Peter R. Herman ◽  
Christopher E. Valdivia ◽  
Vladimir Kitaev ◽  
Geoffrey A. Ozin
Keyword(s):  
Photonic Crystal ◽  
Band Gap ◽  
Optical Fibers ◽  
Photonic Band Gap ◽  
New Type ◽  
Photonic Band

scholarly journals Theoretical Prediction of the Structural and Electronic Properties of a Single Layer Graphene-like Two-dimensional Janus GaInSTe

2021 ◽  
Vol 37 (2) ◽  
Author(s):  
Nguyen Van Chuong ◽  
Nguyen Ngoc Hieu ◽  
Nguyen Van Hieu
Keyword(s):  
Electric Field ◽  
Band Gap ◽  
Electronic Properties ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Two Dimensional ◽  
Direct Band Gap ◽  
Structural And Electronic Properties ◽  
Direct Band ◽  
New Type

This paper constructs a new type of two-dimensional graphene-like Janus GaInSTe monolayer and systematically investigates its structural and electronic properties as well as the effect of external electric field using first-principles calculations. In the ground state, Janus GaInSTe monolayer is dynamically stable with no imaginary frequencies in its phonon spectrum and possesses a direct band gap semiconductor. The band gap of Janus GaInSTe monolayer can be tuned by applying an electric field, which leads the different transitions from semiconductor to metal, and from indirect to direct band gap. These findings show a great potential application of Janus GaInSTe material for designing next-generation devices.

Far Infrared Magnetoabsorption in Hg1-xMnxTe/HgTe Superlattice

1986 ◽  
Vol 89 ◽  
Author(s):  
Z. Yang ◽  
M. Dobrowolska ◽  
H. Luo ◽  
J. K. Furdyna ◽  
K. A. Harris ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Band Gap ◽  
Spin Exchange ◽  
Far Infrared ◽  
Band Offset ◽  
New Type ◽  
Mn Content ◽  
Spin Exchange Interaction ◽  
Valence Bands

Hg-based superlattices (SL)-e.g., the HgTe/CdTe SL–exhibit interesting and important physical properties. Among these are the tunability of the band gap, achieved by varying the thicknesses of the two constituent materials; and the existence of the vajeqnce band offset, on which the details of the valence bands of the SL largely depen. Recently a new type of Hg-based SL, the Hg1-xMnxTe/HgTe SL, has been successfully prepared. In addition to the ability of varying its band gap by controlling the Mn content, this SL has the advantage that some of its important parameters, including the band offset, can be tuned by an external magnetic field because of the spin-spin exchange interaction in the Hg1-xMnxTe layers. So far, the electronic and optical properties of this type of SL have not been explored.

A new compact dual band printed monopole antenna using electromagnetic band gap structures

Circuit World ◽  
2017 ◽  
Vol 43 (2) ◽  
pp. 56-62 ◽  
Author(s):  
El Amjed Hajlaoui
Keyword(s):  
Band Gap ◽  
Monopole Antenna ◽  
Dual Band ◽  
Area Network ◽  
Radiation Patterns ◽  
Electromagnetic Band Gap ◽  
Content Type ◽  
New Type ◽  
Printed Monopole Antenna ◽  
Printed Monopole

Purpose The purpose of this paper is to present a new dual-band printed monopole antenna with a partial ground with two notched bands based on electromagnetic band gap (EBG) structures. A new type of EBG antenna with radiation patterns and antenna gains over the operating bands has been developed. Design/methodology/approach The proposed antenna consists of a pair of EBG structures using a transmission line model. The proposed antenna is designed on an FR4 substrate with a thickness of 1 mm and permittivity (er) = 4.3. Findings The measured results show good dual-band operations with −10 dB impedance bandwidths of 9.1 and 36.2 per cent centered at 2.45 and 6.364 GHz, respectively, which covers the wireless local area network (WLAN) operating bands. Originality/value A new type of EBG antenna with radiation patterns and antenna gains over the operating bands has been developed.

Electronic and Optical Properties of Orientational Superlattices in Gainp Alloys

1999 ◽  
Vol 583 ◽  
Author(s):  
Yong Zhang ◽  
B. Fluegel ◽  
S. P. Ahrenkiel ◽  
D. J. Friedman ◽  
J. F. Geisz ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Gaas Substrate ◽  
Ordered Structure ◽  
Differential Absorption ◽  
Time Resolved ◽  
Electronic And Optical Properties ◽  
Semiconductor Superlattice ◽  
Superlattice Structure ◽  
New Type

AbstractWe demonstrate the formation, and the electronic and optical properties of a novel type of semiconductor superlattice in spontaneously ordered GaInP alloys. The most frequently observed ordered structure in MOCVD grown GaInP has CuPt symmetry where the ordering directions occur in the two [111]B directions, corresponding to two distinct ordered variants. A new type of superlattice, termed an orientational superlattice, emerges as the ordered domains are stacked in a sequence whereby the ordering direction switches alternatively from the [111] direction in one domain to the [111] direction in the next domain. The novelty of this type of superlattice lies in that there is neither a band-gap nor an effective mass discontinuity along the superlattice axis. When the GaInP epilayer is grown on an exact (001) or [111]A tilt GaAs substrate, the two ordered variants are equally favorable. Thus, ordered domain twins appear in ordered GaInP epilayers. We present a comparitive study between the single-variant ordered structure and the double-variant ordered superlattice structure, using TEM and time-resolved differential absorption. We show that for a same order parameter, the band-gap of an orientational superlattice is higher than that of a single-variant ordered structure, and the in-plane optical anisotropy between the [110] and [110]B directions is greatly enhanced due to the superlattice effect. The experimental results are explained in terms of the band structure of the orientational superlattice.

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