scholarly journals New approach to far field analysis for radiation pattern estimation using FDTD method

2014 ◽  
Vol 11 (4) ◽  
pp. 661-672 ◽  
Author(s):  
Bojana Nikolic ◽  
Bojan Dimitrijevic ◽  
Slavoljub Aleksic ◽  
Nebojsa Raicevic ◽  
Nenad Milosevic
Keyword(s):  
Radiation Pattern ◽  
Fdtd Method ◽  
Field Analysis ◽  
High Order Accuracy ◽  
Numerical Dispersion ◽  
Fdtd Simulation ◽  
Efficient Computation ◽  
New Approach ◽  
Complex Envelope ◽  
General Complex

In this paper an approach to efficient computation of radiation pattern in FDTD simulation environment is presented. A necessary large distance from the radiating object is achieved by multigrid space discretization with unilaterally connected subdomains. A numerical dispersion is reduced using more general complex-envelope finite difference time domain (CE-FDTD) formulation and high order accuracy FDTD schemes where possible. In order to examine how much the introduced algorithm complexity and increased demands concerning computational power and memory are justified by the gain in accuracy, several different scenarios were considered.

GPU-Based Acceleration for FDTD Method of Acoustic Field Analysis

2014 ◽  
Vol 602-605 ◽  
pp. 3702-3705
Author(s):  
Ze Rui Yang ◽  
Jie Yang
Keyword(s):  
Acoustic Field ◽  
Time Domain ◽  
Graphics Processing Units ◽  
Large Scale ◽  
Numerical Technique ◽  
Fdtd Method ◽  
Field Analysis ◽  
Fdtd Simulation ◽  
Limiting Factor ◽  
Graphics Processing

The finite difference time domain (FDTD) method is a numerical technique used in time-domain acoustic simulation. However, the huge computing capacity has been an important limiting factor for its applications. In this paper, we will present a graphics processing units (GPU) - based parallel FDTD framework and its successful application to the estimation of time-series sound pressure data. Compared with the computer, the runtime of acoustic field FDTD simulation on GPU is dramatically decreased. The acceleration in runtime has made such study possible, and will pave the way for other studies of large-scale computational acoustic problems which were previously impractical.

scholarly journals Optimising the Complex Refractive Index Model for Estimating the Permittivity of Heterogeneous Concrete Models

2021 ◽  
Vol 13 (4) ◽  
pp. 723
Author(s):  
Hossain Zadhoush ◽  
Antonios Giannopoulos ◽  
Iraklis Giannakis
Keyword(s):  
Refractive Index ◽  
Shape Factor ◽  
Complex Refractive Index ◽  
Fdtd Method ◽  
Air Voids ◽  
Water Fraction ◽  
Index Model ◽  
General Complex ◽  
Ground Penetrating ◽  
Fine Tune

Estimating the permittivity of heterogeneous mixtures based on the permittivity of their components is of high importance with many applications in ground penetrating radar (GPR) and in electrodynamics-based sensing in general. Complex Refractive Index Model (CRIM) is the most mainstream approach for estimating the bulk permittivity of heterogeneous materials and has been widely applied for GPR applications. The popularity of CRIM is primarily based on its simplicity while its accuracy has never been rigorously tested. In the current study, an optimised shape factor is derived that is fine-tuned for modelling the dielectric properties of concrete. The bulk permittivity of concrete is expressed with respect to its components i.e., aggregate particles, cement particles, air-voids and volumetric water fraction. Different combinations of the above materials are accurately modelled using the Finite-Difference Time-Domain (FDTD) method. The numerically estimated bulk permittivity is then used to fine-tune the shape factor of the CRIM model. Then, using laboratory measurements it is shown that the revised CRIM model over-performs the default shape factor and provides with more accurate estimations of the bulk permittivity of concrete.

scholarly journals UWB elliptical patch monopole antenna with dual-band notched characteristics

2019 ◽  
Vol 9 (5) ◽  
pp. 3591
Author(s):  
A H Majeed ◽  
K H Sayidmarie
Keyword(s):  
Radiation Pattern ◽  
Ground Plane ◽  
Monopole Antenna ◽  
Experimental Results ◽  
Dual Band ◽  
New Approach ◽  
Compact Size

<p class="Default">In this paper, a new approach to the design of an UWB monopole antenna with dual band-notched characteristics is presented.   The antenna has the form of an elliptical monopole over a ground plane having an elliptical slot to achieve the UWB. The dual-band notch function is created by inserting a U-shaped and a C-shaped slots on the radiating patch, thus no extra size is needed. The proposed antenna shows a good omnidirectional radiation pattern across the band from 3.2 to more than 14 GHz. The dual band-rejection is for 4.88-5.79GHz centered at 5.4GHz and 7.21-8.46 GHz centered at 7.8 GHz. The antenna prototype using the FR-4 substrate with ε<sub>r</sub>=4.3 has a compact size of 25mm×25 mm ×1.45mm. The fabricated prototype showed experimental results comparable to those obtained from the simulations.</p>

scholarly journals Efficient Computation of Highly Oscillatory Fourier Transforms with Nearly Singular Amplitudes over Rectangle Domains

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1930
Author(s):  
Zhen Yang ◽  
Junjie Ma
Keyword(s):  
Adaptive Mesh Refinement ◽  
Numerical Experiments ◽  
Singular Integrals ◽  
Fourier Transforms ◽  
Adaptive Mesh ◽  
Oscillatory Integrals ◽  
Efficient Computation ◽  
New Approach ◽  
Highly Oscillatory ◽  
Nearly Singular Integrals

In this paper, we consider fast and high-order algorithms for calculation of highly oscillatory and nearly singular integrals. Based on operators with regard to Chebyshev polynomials, we propose a class of spectral efficient Levin quadrature for oscillatory integrals over rectangle domains, and give detailed convergence analysis. Furthermore, with the help of adaptive mesh refinement, we are able to develop an efficient algorithm to compute highly oscillatory and nearly singular integrals. In contrast to existing methods, approximations derived from the new approach do not suffer from high oscillatory and singularity. Finally, several numerical experiments are included to illustrate the performance of given quadrature rules.

scholarly journals An Artificial Anisotropy Four-Step HIE-FDTD Method With Lower Numerical Dispersion Error

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 199016-199024
Author(s):  
Yong-Dan Kong ◽  
Chu-Bin Zhang ◽  
Hong-Yu Zhang ◽  
Qing-Xin Chu
Keyword(s):  
Fdtd Method ◽  
Numerical Dispersion ◽  
Dispersion Error

scholarly journals Considerations for the Design of UWB Antennas for Mobile and Consumer Equipment

2005 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Dirk Manteuffel
Keyword(s):  
Radiation Pattern ◽  
Power Distribution ◽  
Ultra Wideband ◽  
Fdtd Simulation ◽  
Single Frequency ◽  
Frequency Dependency ◽  
Propagation Modeling ◽  
Antenna Performance ◽  
Received Power ◽  
The Impact

This paper presents some considerations on the design, characterization and optimization of UWB (Ultra WideBand) antennas for consumer communication equipment. As a first step a method to extract the spatio-temporal UWB antenna characterization from a FDTD simulation is given. Thereafter, the shape of a planar monopole is optimized to provide broadband matching. This is followed by the integration of latter antenna into a model of a DVD player and the impact of this integration on the antenna performance is evaluated. Finally, the transfer function of the complete system is extracted and used for indoor propagation modeling in an exemplary living home environment. The results show that the antenna integration into the DVD-chassis results into a directive radiation pattern that shows a significant frequency dependency. When this antenna is used for the propagation modeling, a single frequency ray-tracing simulation shows significant variation in the radiated power distribution in the room as a result of the directive pattern. When the received power is averaged over a larger bandwidth, the coverage becomes more smooth mainly due to the frequency dependency of the radiation pattern and frequency dependent propagation effects. Indeed, comparing the results of the integrated antenna to the case of the ideal isotropic radiator, no major disadvantages can be discerned anymore.

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