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Comparison between Rectangular and Triangular Patch Antennas Arrays  [cached]
Yahya S. H. khraisat,Melad M. Olaimat,Sharief N. Abdel-Razeq
Applied Physics Research , 2012, DOI: 10.5539/apr.v4n2p75
Abstract: In this paper, several designs of micorstip arrays antennas, suitable for wireless communication applications, are presented. This paper demonstrates several shapes of microstrip array antennas, such as rectangular and triangular patch antennas array. Specifically, 4x1, 2x1, and single element of both shapes are designed and simulated by a full wave simulator (IE3d). Moreover, this paper presents a comparison between both rectangular and triangular antenna arrays. Since, the resonance frequency of these antennas is 2.4 GHz, these antennas are suitable for ISM band and WLAN.
Circularly Polarized Arrays of Cavity Backed Slot Antennas for X-Band Satellite Communications
Eman M. A. Eldesouki;Khalid Fawzy Ahmed Hussein;Adel M. El-Nadi
PIER B , 2008, DOI: 10.2528/PIERB08080302
Abstract: Circularly-polarized arrays of cavity backed slot (CBS) antennas are proposed for X-band satellite-earth communications. Two configurations of such circularly polarized arrays are investigated: cross-shaped and square-shaped arrays. Both configurations can produce right-hand circular polarization (RHCP) as well as lefthand circular polarization (LHCP) by proper setting of excitation phase for each element in the array. The finite-difference timedomain (FDTD) method is used to analyze the characteristics of the proposed arrays including the input impedance, -parameters, radiation pattern, gain and axial ratio. The results show that the proposed array configurations seem very promising and useful for geostationary satellite applications.
Multi-Layered Ring Log-Periodic Antennas Array Design for GPS Systems
M. Abri,S.M. Bahloul,H. Abri Badaoui
International Journal of Computer Networks & Communications , 2012,
Abstract: The objective of the present study is the design of log periodic ring printed antennas array witch generates circular polarization with wide band by single feed linearly polarized elements for GPS systems. The radiating elements have been fed by magnetic coupling through a slot. The circular polarization is achieved by having a basic 2×2 sub-arrays with unique element angular and phase arrangement, both the element angular orientation and feed phase are arranged in the 0°, 90°, 180 and 270° fashion. The purpose of different angular orientations of the patches is to generate two orthogonally polarized fields, while -3dB coupler is used to provide the required amplitude and phase delays for circular polarization generation. This uniquely formed array has the capability of generating excellent circular polarization. An association of the coupler with the antennas has been established.This work is completed using the moment’s method of Momentum software. Good performances of adaptation and polarization were obtained. The simulation results are then presented and discussed.
Enhancing the Directivity of Phased Array Antennas Using Lens-Arrays
Abbas Abbaspour-Tamijani;Lisha Zhang;Helen K. Pan
PIER M , 2013, DOI: 10.2528/PIERM12062702
Abstract: Small phased-array antennas can be combined with dielectric lenses or planar lens-arrays to form directive beam-steering system. The use of the lens increases the size of the radiating aperture and enhances the directivity of the phased array, but it also reduces its scan field of view. However, the effect can be controlled by properly designing the phase delay profile across the lens. This paper presents the formulation and methodology for designing modified lenses that can allow the desired scan angle. The utility and limitations of the proposed approach will be illustrated by considering several design examples. Simulations suggest that a directivity enhancement of > 2 dB and wide scan field of view (up to 45° off boresight) can be obtained for compact radiation systems employing small lenses and short separations between the lens and phased array. Larger directivity improvements in the range of tens of dB's are possible in systems with limited scanning capability by employing large lenses and greater phased array-lens separation. Ease of implementation and the ability of the proposed topology to adapt to the system requirements make this topology an interesting candidate for various millimeter-wave radio applications.
Patterns Antennas Arrays Synthesis Based on Adaptive Particle Swarm Optimization and Genetic Algorithms  [PDF]
Boufeldja Kadri,Miloud Bousahla,Mohamed Brahimi,Ismail Khalil Bousserhane
International Journal of Computer Science Issues , 2013,
Abstract: In recent years, evolutionary optimization (EO) techniques have attracted considerable attention in the design of electromagnetic systems of increasing complexity. This paper presents a comparison between two optimization algorithms for the synthesis of uniform linear and planar antennas arrays, the first one is an adaptive particle swarm optimization (APSO) where the inertia weight and acceleration coefficient are adjusted dynamically according to feedback taken from particles best memories to overcome the limitations of the standard PSO which are: premature convergence, low searching accuracy and iterative inefficiency. The second method is the genetic algorithms (GA) inspired from the processes of the evolution of the species and the natural genetics. The results show that the design of uniform linear and planar antennas arrays using APSO method provides a low side lobe level and achieve faster convergence speed to the optimum solution than those obtained by a GA.
Synthesis of Antenna Arrays and Parasitic Antenna Arrays with Mutual Couplings
M. Thevenot,C. Menudier,A. El Sayed Ahmad,G. Zakka El Nashef,F. Fezai,Y. Abdallah,E. Arnaud,F. Torres,T. Monediere
International Journal of Antennas and Propagation , 2012, DOI: 10.1155/2012/309728
Abstract: A synthesis method to design multielement antennas with couplings is presented. The main objective is to perform a rigorous determination of the electromagnetic characteristics involved in the design, especially with arrays of moderate sizes. The aim is to conceive jointly and efficiently the antenna and the circuits to connect (feed distribution network, power amplifiers, reactive loads, etc.). The subsequent objective is to improve the understanding and capabilities of strongly coupled antennas. As a whole, the synthesis procedure is then applied to different antenna architectures in order to show its efficiency and versatility. A focus on some antenna concepts where the management of couplings is a key factor to improve the performances is presented. After describing the synthesis procedure, the first category of coupled multielement antenna studied concerns radiating arrays in linear or circular polarization. A design including couplings effects on an active array is also presented. Then, the method is applied to parasitic antenna arrays and a specific investigation on reflectarray antenna is performed as they can be considered as a particular case of parasitic arrays.
New Configurations of Low-Cost Dual-Polarized Printed Antennas for UWB Arrays
Guido Valerio,Simona Mazzocchi,Alessandro Galli,Matteo Ciattaglia,Marco Zucca
International Journal of Antennas and Propagation , 2012, DOI: 10.1155/2012/786791
Abstract: A novel class of structures is proposed to realize ultra-wide-band radiating elements for large arrays, providing dual polarization, beam scanning, and compact and inexpensive realization based on suitable rhombic arrangements of dipoles printed on low-cost layered substrates. In a first implementation, four rhombic shapes, orthogonally placed on the same layer, provide two orthogonal polarizations. In a second implementation, the two polarizations are excited by two rhombic shapes printed on two different layers in a stacked-patch-like arrangement. This latter structure leads to a better lateral shielding of the single radiating element, in order to reduce mutual interactions among adjacent elements in array environment. The behavioral features of these antennas have been tested with various parametric analyses. Practical aspects have been addressed such as the choice of appropriate feeding and of commercially available dielectric layers. The resulting antennas are matched at the input ports in an extremely wide range of frequencies (5–25 GHz), covering various microwave applications, such as aircraft surveillance, weather polarimetric radars, and control and communications systems. Good radiating features, in terms of pattern shape and gain, are observed in a large band of frequencies. The basic scanning performance of large and small array configurations is finally investigated.
Parabolic antennas, and circular slot arrays, for the generation of Non-Diffracting Beams of Microwaves  [PDF]
Michel Zamboni-Rached,Erasmo Recami
Physics , 2014,
Abstract: We propose in detail Antennas for generating Non-Diffracting Beams of Microwaves, for instance with frequencies of the order of 10 GHz, obtaining fair results even when having recourse to realistic apertures endowed with reasonable diameters. Our first proposal refers mainly to sets of suitable annular slits, having in mind various possible applications, including remote sensing. Our second proposal --which constitutes one of the main aims of this paper-- refers to the alternative, rather simple, use of a Parabolic Reflector, illuminated by a spherical wave source located on the paraboloid axis but slightly displaced with respect to the Focus of the Paraboloid. Such a parabolic reflector yields "extended focus" (non-diffracting) beams. [OCIS codes: 999.9999; 070.7545; 050.1120; 280.0280; 050.1755; 070.0070; 200.0200. Keywords: Non-Diffracting Waves; Microwaves; Remote sensing; Annular Arrays; Bessel beams; Extended focus; Reflecting paraboloids; Parabolic reflectors; Parabolic antennas].
Performance Analysis of Corporate Feed Rectangular Patch Element and Circular Patch Element 4x2 Microstrip Array Antennas  [PDF]
Md. Tanvir Ishtaique-ul Huque,Md. Al-Amin Chowdhury,Md. Kamal Hosain,Md. Shah Alam
International Journal of Advanced Computer Sciences and Applications , 2011,
Abstract: This paper present simple, slim, low cost and high gain circular patch and rectangular patch microstrip array antenna, with the details steps of design process, operate in X-band(8 GHz to 12 GHz) and it provides a mean to choose the effective one based on the performance analysis of both of these array antennas. The method of analysis, design and development of these array antennas are explained completely here and analyses are carried out for 4x2 arrays. The simulation has been performed by using commercially available antenna simulator, SONNET version V12.56, to compute the current distribution, return loss response and radiation pattern. The proposed antennas are designed by using Taconic TLY-5 dielectric substrate with permittivity, εr = 2.2 and height, h =1.588 mm. In all cases we get return losses in the range -4.96 dB to -25.21 dB at frequencies around 10 GHz. The gain of these antennas as simulated are found above 6 dB and side lobe label is maintained lower than main lobe. Operating frequency of these antennas is 10 GHz so these antennas are suitable for X-band application.
Performance Analysis of Corporate Feed Rectangular Patch Element and Circular Patch Element 4x2 Microstrip Array Antennas
Md. Tanvir Ishtaique-ul Huque,Md. Al-Amin Chowdhury,Md. Kamal Hosain,Md. Shah Alam
International Journal of Advanced Computer Sciences and Applications , 2011,
Abstract: This paper present simple, slim, low cost and high gain circular patch and rectangular patch microstrip array antenna, with the details steps of design process, operate in X-band(8 GHz to 12 GHz) and it provides a mean to choose the effective one based on the performance analysis of both of these array antennas. The method of analysis, design and development of these array antennas are explained completely here and analyses are carried out for 4x2 arrays. The simulation has been performed by using commercially available antenna simulator, SONNET version V12.56, to compute the current distribution, return loss response and radiation pattern. The proposed antennas are designed by using Taconic TLY-5 dielectric substrate with permittivity, er = 2.2 and height, h =1.588 mm. In all cases we get return losses in the range -4.96 dB to -25.21 dB at frequencies around 10 GHz. The gain of these antennas as simulated are found above 6 dB and side lobe label is maintained lower than main lobe. Operating frequency of these antennas is 10 GHz so these antennas are suitable for X-band application.
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