scholarly journals Design of a Wide Dual-Band Coplanar Probe Feed Antenna for WLANs Applications

2020 ◽  
Vol sceeer (3d) ◽  
pp. 13-16
Author(s):  
Nabil Abdulhussein ◽  
Abdulkareem Abdullah
Keyword(s):  
Finite Difference Time Domain ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Dual Band ◽  
Operating Frequency ◽  
Center Frequency ◽  
Ieee 802.11B ◽  
Ieee 802.11A ◽  
Domain 3 ◽  
Difference Time

This paper presents a new design to obtain wide dual-band operation from a coplanar probe feed antenna loaded with two shorted walls. The lower band of proposed antenna has a 10 dB bandwidth of 611 MHz (24.18%) around the center frequency 2527MHz, and the upper band has a bandwidth of 1255 MHz (27.88%) around the center frequency 4501MHz. The obtained bandwidths cover WLANs operations on all bands. The bandwidth of the first operating frequency covers ISM band (2400-2483.5) MHz, which is required by IEEE 802.11b, g and Bluetooth standards, and the bandwidth of the second operating frequency covers U-NII1 (5150-5350) MHz band, which is required by IEEE 802.11a and HiperLAN2 standards, and also covers U-NII2 (5470-5725) MHz and U-NII3/ISM (5725-5825) MHz bands, which are required by IEEE 802.11a standard. A three dimensional finite-difference time-domain (3-D FDTD) method is employed to analyze the proposed structure and find its performance. The simulated results are compared with the experimental results.

scholarly journals Defects-Induced Hot Spots in TATB

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhonghua Yan ◽  
Chuanchao Zhang ◽  
Hongwei Yan ◽  
Zhijie Li ◽  
Li Li ◽  
...  
Keyword(s):  
Hot Spots ◽  
Energetic Materials ◽  
Finite Difference Time Domain ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Laser Ignition ◽  
Ignition Process ◽  
Incident Laser ◽  
Three Dimensional Models ◽  
Difference Time

We investigate the interaction between the laser and energetic materials with different defects. The three-dimensional models of triaminotrinitrobenzene (TATB) explosives containing spherical pores, craters, and cracks are established, respectively. The laser ignition process of TATB is simulated with three-dimensional finite difference time domain (3D-FDTD) method to study the electromagnetic field distribution surrounding these defects with 355 nm laser incidence. It indicates that the larger defects in the TATB energetic materials have the stronger electric field modulations to initial incident laser for all the three defects, which is easier to lead to the generation of hot spots. Furthermore, TATB materials with spherical pore defects and crater defects are easier to form hot spots than those with narrow crack defects.

The CPML for Hybrid Implicit-Explicit FDTD Method Based on Auxiliary Differential Equation

2014 ◽  
Vol 989-994 ◽  
pp. 1869-1872 ◽  
Author(s):  
Yun Fei Mao ◽  
Pu Hua Huang ◽  
Li Guo Ma
Keyword(s):  
Differential Equation ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Complex Frequency ◽  
Numerical Examples ◽  
First Order ◽  
Contour Plots ◽  
Difference Time

In this paper, an implementation of the complex-frequency-shifted perfectly matched layer (CPML) is developed for three-dimensional hybrid implicit-explicit (HIE) finite-difference time-domain (FDTD) method based on auxiliary differential equation (ADE). Because of the use of the ADE technique, this method becomes more straightforward and easier to implement. The formulations for the HIE-FDTD CPML are proposed. Numerical examples are given to verify the validity of the presented method. Results show that, both HIE-CPML and FDTD-CPML have almost the same reflection error, while their reflection error is about 30 dB, which is less than HIE Mur’s first-order results. The contour plots indicate that the maximum relative reflection as low as-72 dB is achieved by selecting and .

scholarly journals Numerical Analysis of Ridged-Circular Nanoaperture for Near-Field Optical Disk

ISRN Optics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Toshiaki Kitamura
Keyword(s):  
Phase Change ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Near Field ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Free Electrons ◽  
Metallic Material ◽  
Motion Equations ◽  
Difference Time

A ridged-circular nanoaperture is investigated through three-dimensional (finite-difference time-domain) FDTD method. The motion equations of free electrons are inserted to analyze a metallic material. The electromagnetic field distributions of optical near-field around the aperture are investigated. The phase change disk illuminated by a near-field optical light through a ridged-circular nanoaperture is also analyzed. The far-field scattering patterns from the phase change disk and the crosstalk characteristics between plural marks are studied.

Three-Dimensional Finite-Difference Time-Domain Method Modeling of Nanowire Optical Probe

2014 ◽  
Vol 602-605 ◽  
pp. 3359-3362
Author(s):  
Chun Li Zhu ◽  
Jing Li
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Incident Light ◽  
Near Field ◽  
Three Dimensional ◽  
Polarization Direction ◽  
Near Field Imaging ◽  
Difference Time ◽  
Field Imaging

In this paper, output near fields of nanowires with different optical and structure configurations are calculated by using the three-dimensional finite-difference time-domain (3D FDTD) method. Then a nanowire with suitable near field distribution is chosen as the probe for scanning dielectric and metal nanogratings. Scanning results show that the resolution in near-field imaging of dielectric nanogratings can be as low as 80nm, and the imaging results are greatly influenced by the polarization direction of the incident light. Compared with dielectric nanogratings, metal nanogratings have significantly enhanced resolutions when the arrangement of gratings is perpendicular to the polarization direction of the incident light due to the enhancement effect of the localized surface plasmons (SPs). Results presented here could offer valuable references for practical applications in near-field imaging with nanowires as optical probes.

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