scholarly journals High Directivity Broadband Hexagonal Fractal Ring Antenna with Modified Ground

Author(s):  
Tharanga Premathilake ◽  
Jeevani Jayasinghe ◽  
Omar Saraereh ◽  
Karu Esselle ◽  
Rajas Khokle

A highly directive fractal antenna with a novel shape is proposed in this paper. Finite Element Method based simulations were carried out on the first three iterations of a hexagonal fractal ring and the performance was measured in terms of the resonant behavior, directivity, radiation efficiency, current distribution, and radiation pattern. The second iteration fractal antenna radiates well along the broadside direction at the fundamental mode of operation. The ground plane was modified to improve the performance further. The antenna, etched on an FR4 substrate, has a directivity of 11.8 dB along the broadside direction with multi-frequency broadband performance over the frequency range of 3.12-7.46 GHz. Therefore, the proposed fractal antenna can be used for Wireless LAN applications. The antenna was fabricated and measured in order to validate the results.

A Co-planar wave guide fed rectangular ring antenna for WiFi and 5G applications is proposed in this paper. The operating frequency of the antenna is centered at two frequencies i.e 2.52GHz and 3.65GHz which are in S-band frequency spectrum. The main radiator is rectangular ring for whose inner corners are smoothed. The similar structure of the main radiator is etched from the ground plane making the proposed technique a fractal. For the proposed antenna FR4 laminate is used as substrate and a line feed is used to provide excitation. To achieve the high wide bandwidth we have implemented the fractal technique. The antenna size is 60mm×60mm×1.6mm and is radiating in the frequency range of 2.27GHz to 2.67GHz covering 400MHz of bandwidth and 3.5GHz to 3.82GHz covering 320MHz of bandwidth.


2017 ◽  
Vol 6 (3) ◽  
pp. 64
Author(s):  
R. Sahoo ◽  
D. Vakula

In this paper, a novel wideband conformal fractal antenna is proposed for GPS application. The concepts of fractal and partial ground are used in conformal antenna design for miniaturization and bandwidth enhancement. It comprises of Minkowski fractal patch on a substrate of Rogers RT/duroid 5880 with permittivity 2.2 and thickness of 0.787mm with microstrip inset feed. The proposed conformal antenna has a patch dimension about 0.39λmm×0.39λmm, and partial ground plane size is 29mm×90mm.The proposed antenna is simulated, fabricated and measured for both planar and conformal geometry, with good agreement between measurements and simulations. The size of the fractal patch is reduced approximately by 32% as compared with conventional patch. It is observed that the conformal antenna exhibits a fractional bandwidth(for the definition of -10dB) of 43.72% operating from 1.09 to 1.7GHz, which is useful for L1(1.56-1.58GHz), L2(1.21-1.23GHz), L3(1.37-1.39GHz), L4(1.36-1.38GHz), and L5(1.16-1.18 GHz) in GPS and Galileo frequencies: E=1589.742MHz(4MHzbandwidth), E2=1561. 098MHz(4MHzbandwidth), E5a=1176.45MHz(=L5),E5b= 1207.14MHz, and E6=1278.75MHz(40MHz bandwidth). The radiation pattern exhibits an omnidirectional pattern, and gain of proposed antenna is 2.3dBi to 3.5dBi within operating frequency range.


Author(s):  
Takuya Hiraguri ◽  
Syun Sakurai ◽  
Koichi Karasawa ◽  
Hidetoshi Nakayama ◽  
Kazuki Ashida ◽  
...  

2019 ◽  
Vol 17 (09) ◽  
pp. 1950060
Author(s):  
Tengfei Dai ◽  
Xia Jin ◽  
Huaze Yang ◽  
Tianran Lin ◽  
Yuantong Gu

Modeling and simulation of the acoustic response in enclosed cavities of a diesel engine are of great significance for optimal design of an engine to achieve a better acoustic performance. Nevertheless, the use of the traditional finite element method (FEM) for the mid to high frequency acoustic prediction is limited by the well-known numerical dispersion errors and the tedious preprocessing of the model. Smoothed finite element methods (SFEMs) proposed originally for solid mechanics have been employed for the modeling of acoustic problems in the low to medium frequency ranges whilst acoustic modeling in the mid to high frequency range remains untouched. This paper comprehensively investigates into the performance of SFEMs in modeling and simulation of mid to high frequency acoustic problems. It is shown that the mass-redistributed edge-based smoothed finite element method (MR-ES-FEM) can yield an excellent prediction result in the mid to high frequency range in terms of accuracy, efficiency and robustness. The MR-ES-FEM is also used to simulate sound propagation in a cylinder head chamber of a four-cylinder diesel engine to prove its effectiveness. The findings presented in this paper offer an in-depth insight for engineers to select suitable numerical methods for solving mid to high frequency acoustic problems in the design of diesel engines.


2018 ◽  
Vol 196 ◽  
pp. 01055
Author(s):  
Sławomir Dudziak ◽  
Zofia Kozyra

Dynamic analyses play an important role in the process of designing buildings in the vicinity of transportation routes. The Finite Element Method is the most popular modelling technique, because it allows to simulate the structure response in the higher frequency range properly. However, the results of such analyses depend on many factors and can differ a lot. This paper discusses the impact of the building mass estimation and neglecting or including damping in the analysis on the assessment of influence of vibrations due to traffic on people.


1999 ◽  
Author(s):  
Xi Zhao ◽  
Nickolas Vlahopoulos

Abstract The theoretical development of a hybrid finite element method is presented. It combines conventional Finite Element Analysis (FEA) with Energy Finite Element Analysis (EFEA) in order to achieve a numerical solution to mid-frequency vibrations. In the mid-frequency range a system is comprised by some members that contain several wavelengths and some members that contain a small number of wavelengths. The former are considered long members and they are modeled by the EFEA. The latter are considered short and they are modeled by the FEA. The new formulation is based on deriving appropriate interface conditions at the joints between sections modeled by the EFEA and the FEA methods. Since the work presented in this paper constitutes a fundamental step in the development of a hybrid method for mid-frequency analysis, the formulation for one flexural degree of freedom in co-linear beams is presented. The excitation is considered to be applied on a long member and the response of the entire system is computed. Uncertainty effects are imposed only on the long members of the system. Validation cases for several configurations are presented.


Sign in / Sign up

Export Citation Format

Share Document