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Applied Electromagnetics Conference (AEMC), 2009

Date 14-16 Dec. 2009

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Displaying Results 1 - 25 of 161
  • [Front cover]

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    Freely Available from IEEE
  • Table of content

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    Freely Available from IEEE
  • The resonant frequency optimization of aperture-coupled microstrip antenna using particle swarm optimization algorithm

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (347 KB) |  | HTML iconHTML  

    Aperture coupled microstrip antenna is gathering a lot of interest in communication and radar systems. Particle swarm optimization (PSO) has been introduced to the electromagnetic community recently for design optimization of microstrip patch antenna .In this paper PSO has been used for accurate determination of resonant frequency of rectangular aperture-coupled microstrip antenna. The investigation is made at different microwave frequency ranges and it extends up to Ku band. The procedure is repeated for different dielectric constant of antenna and feed substrate. The optimization problem has three variables namely, aperture length, aperture width and stub length respectively. Accuracy of the results encourages the use of PSO. View full abstract»

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  • Microstrip patch antenna on photonic crystal substrate at terahertz frequency

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    In this paper, a dielectric slab with the periodic implantation of the air gap in the host passive substrate material has been analyzed. The effective permittivity of the photonic crystal with host material PTFE at 600 GHz has been extracted with the help of robust method to retrieve the constitutive effective parameters of the metamaterials. Based on the extracted effective permittivity, a rectangular microstrip patch antenna at terahertz regime of the electromagnetic spectrum on the 2-D photonic crystal has been designed and simulated by using CST Microwave Studio, a commercially available simulator based on the finite integral technique. View full abstract»

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  • Dual-frequency terahertz rectangular microstrip patch antenna on photonic crystal substrate

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    In this paper, the effects of 2-D photonic crystal substrate on the performance of a rectangular microstrip patch antenna at terahertz frequency (0.4-0.8THz) has been investigated. The photonic substrate has been used to enhance the gain and radiation efficiency of the proposed antenna. The gain and radiation efficiency of this antenna at 600 GHz is about 13dB and 83.02%, respectively. This antenna resonates at 575 and 741GHz. For the comparison of the gain in two principle planes at 600 GHz, the structure has been simulated by two different simulators CST Microwave Studio and Ansoft HFSS. View full abstract»

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  • Dual frequency planar microstrip antenna

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    In this paper a simple technique to develop a two layer dual frequency antenna with identical polarization at two far apart frequencies has been presented. Dual rectangular resonator proximity coupled planar microstrip antennas has been designed, fabricated and tested. The design optimisation was carried out using commercial MoM based simulation software. The patch width, intermediate spacing between the coplanar patches are optimized by successive simulations using the commercial software. Measured gain at both the frequencies is over 6 dBi. Measured results are also presented. View full abstract»

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  • Single-feed compact wideband elliptical patch antenna with narrow slits

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (233 KB) |  | HTML iconHTML  

    This paper presents the radiation performance of a modified elliptical patch microstrip antenna (EPMA) simulated on glass epoxy FR4 substrate material. For modification in patch geometry, two parallel narrow slits in the EPMA geometry parallel to its minor axis are applied. In this way, patch is divided in three patches. The two outer patches are identical in shape and size. The central patch is excited through inset feed and the two outer patches are gap coupled to this center patch. The modified antenna resonates at two closely spaced frequencies with much improved bandwidth (> 10%). The radiation patterns of antenna at four frequencies considered in the range where antenna displays broadband behaviour are almost identical in shape and nature. The gain and directivity of antenna displays variation of less than 1 dBi within considered frequency range. The simulation results suggest that this antenna with little more improvisations may be a suitable candidate for Wi-MAX applications. View full abstract»

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  • Rectangular microstrip antenna for dual-band operation

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    The series and shunt inductivity introduced by the probe and shorting pin respectively in a single-feed shorted rectangular microstrip antenna has been evaluated theoretically using transmission line method. The proposed structure provides compact dual band operation using single feed mechanism. The input impedance, VSWR, and return loss are calculated theoretically. It is found that the ratio of the resonant frequencies highly depends on the position of shorting pin. View full abstract»

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  • Slotted single layer broadband rectangular patch antennas

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (389 KB) |  | HTML iconHTML  

    Three different slotted broadband single layer rectangular patch antennas having improved radiation patterns and gain are presented. A single I- shaped slot single layer rectangular patch antenna gives an impedance bandwidth (-10dB return loss) of 24.39% with an average gain of about 10.51 dBi over the entire passband and peak gain of 11.04 dBi. With double I- slot an impedance bandwidth (-10dB return loss) of 27.88% with average gain of about 9.95 dBi over the entire passband and peak gain of 10.27 dBi have been achieved. Another single T-shaped slot broadband single layer rectangular patch antenna with impedance bandwidth of 25.23% with average gain of about 7.43 dBi over the entire passband and peak gain of 9.88 dBi is presented. The IE3D simulation software based on Method of Moments (MoM) is used for simulation and Agilent's E5071B ENA series Network Analyzer is used for measurements. Air substrate (??r = 1) is used for simulation and foam (??r ?? 1) is used to support patch for experimental purposes. Both simulated and measured results are presented. View full abstract»

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  • On the design of CPW-fed square octal shaped fractal UWB antenna

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    This paper presents the design of an ultra wide band (UWB) antenna with CPW-fed. The antenna has been designed on FR4 substrate ??r = 4.3 and thickness 1.53 mm. The antenna has been fabricated and tested using VNA. The experimental results of this antenna offer ultra wide bandwidth from 2.86 GHz to 14.38 GHz. This corresponds to the impedance bandwidth 11.42 GHz and 132.48 %. The experimental results also exhibits the first band from 0.62 GHz to 1.657 GHz corresponds to 1.037 GHz bandwidth. The radiation pattern of this antenna is nearly omni directional. This type of antenna can be used for ultra wide band system, positioning system, microwave imaging and Radar application. View full abstract»

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  • Design of a single layer multiband microstrip square ring antenna

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    The characteristics of a compact, slotted microstrip square ring antenna are investigated. It achieves multiband and wideband functionality through the addition of the circular slots in the dielectric and ground plane of the square ring antenna. The antenna is analyzed in the frequency band of 1 - 30 GHz. The antenna exhibits radiation characteristics in L, S, C, X, Ku, and K bands. Investigations on the radiation characteristics have also been carried out and the results are presented. View full abstract»

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  • Broad band parasitically coupled concentric semi circular elliptically ring antenna surrounding an elliptical patch with air gap

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (222 KB) |  | HTML iconHTML  

    The paper presents the performance of a parasitically coupled semi circular elliptical ring antenna surrounding elliptical patch geometry having air gap between conducting patch and ground plane. With proposed modifications in the conventional circular patch geometry, the bandwidth of modified antenna with an air gap is around seven times higher than that of a simple circular patch antenna. The gain, directivity and efficiency of modified circular patch antenna with air gap is also improved to some extent but still these are less than desired values. The E and H plane radiation patterns presented by antenna in the frequency range where broadband performance is obtained are identical in shape and nature. Direction of maximum intensity retained by antenna at both frequencies is normal to patch geometry. View full abstract»

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  • A novel approach for efficiency enhancement and size miniaturization of UWB antennas

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (500 KB) |  | HTML iconHTML  

    The printed antenna is one of the most preferred antenna structures for low cost and compact design of wireless communication systems. In this paper we have investigated a new approach for improving the radiation efficiency and performance of the antennas with the size miniaturization, in particular we have simulated two types of UWB printed monopole antennas for proving this approach with results: circular patch and Compact Miniaturized Semi-Circular patch UWB monopole antennas and in detail investigation was presented on size miniaturization in order to achieve very compactness and high radiation efficiency with out degradation of the functional parameters and overall performance. Simple rectangular microstrip lines are used for feeding the printed monopole antennas. This UWB monopole antenna designed works well for the whole UWB frequency band 3.1-10.6 GHz. View full abstract»

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  • Rectangular patch antenna with orthogonal crossed slits

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (229 KB) |  | HTML iconHTML  

    A compact rectangular patch antenna with narrow crossed slits is proposed in this paper that is resonating at two closely spaced frequencies (3.56 GHz, 3.73 GHz) with improved bandwidth (7.6%). This bandwidth value is more than three times higher than that of a conventional rectangular patch antenna (~2%) having identical patch size and operating under similar conditions. The variation in gain and directivity of proposed antenna in the frequency range where broadband performance is recorded is less than 2dBi but it needs further reduction. The gain and efficiency of proposed antenna are little higher than that of a conventional rectangular patch antenna but these are still lower than desired values. The radiation patterns drawn at two resonance frequencies are identical in shape and nature. These obtained parameters suggest that proposed antenna may be proved useful for modern communication systems when designed on low loss substrates. View full abstract»

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  • Study and comparison of RCS of microstrip patch antennas on LiTi-ferrite substrate

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2033 KB) |  | HTML iconHTML  

    Radar cross sections (RCS) of rectangular, circular and triangular microstrip patch antennas are presented which are printed on LiTi ferrite substrate in X-band (8-12 GHz) region. In this paper, we precise the preparation of a polycrystalline LiTi ferrite of 2200 Gauss saturation magnetization. The comparison of RCS patterns among RPMA, CPMA and TPMA shows the affective study of radar cross section which differentiates the stealth capacity as well as miniaturization due to the ferrite substrate application. View full abstract»

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  • A wideband Sierpinski carpet fractal cylindrical dielectric resonator antenna for X-Band application

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    A wideband Sierpinski carpet fractal patterned embedded DRA is presented in this paper. Antenna design methodology is discussed along with its resonance and radiation characteristics. An impedance bandwidth of 50% is obtained covering the entire X-band with similar radiation pattern throughout the band. The average peak gain within the band is about 5.5 dBi. View full abstract»

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  • A versatile beam steering double square loop antenna for modern wireless communications

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5889 KB) |  | HTML iconHTML  

    A novel method of producing and switching multiple beams using double square loop (DSL) antenna is proposed. By switching the feed point, the pattern can be steered at a coarse step of 45?? throughout the 360?? of space and the associated beam can be directed in eight directions, thus offering a wide range of options for modern wireless devices to focus the beam at a desired target direction. Furthermore, with varying permittivity value of dielectric substrate, the DSL produces axial and tilted beams of fine varying degree of elevation. The variation in the permittivity can be achieved electronically by using substrates made up of materials such as liquid crystals or ferro-electric materials (Barium Titanate, Barium Strontium Titanate or Lead Titanate) which may be constituted in a fine grained random polycrystalline or a ceramic form. The average gain of antenna beams is 8.2dBi. The beam steerable DSL antenna is designed to operate in the frequency band of 2.5 GHz to 5.8 GHz and is very likely to have direct applications in high data rate systems such as UWB, WIMAX and 4G networks. View full abstract»

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  • Bandwidth enhancement of microstrip antennas using shifted parasitically coupled planar multiresonators

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    In this paper, a wideband planar multi resonator antenna with parasitic coupling is proposed and studied. Impedance and radiation characteristics of this antenna are presented and discussed. From the results, it has been observed that, the Impedance bandwidth, defined by 10 dB return loss, can reach an operating bandwidth of 251 MHz with center operating frequency of 3023 MHz, which is about four times that of conventional reference patch antenna. The gain of studied antenna is also observed with peak gain of about 8.33 dBi. View full abstract»

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  • Metal loaded miniaturized CPW fed DRA

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (231 KB) |  | HTML iconHTML  

    Recently, there has been an increased interest in the realization of miniaturized and high capacity transceiver systems. The dielectric resonator antenna ( DRA ) has been an ideal candidate for low-loss and broadband microwave and millimeter wave applications. The coplanar waveguide ( CPW ) feed has been proposed as an efficient feed topology to the DRA due to its low loss, dispersion, ease of active integration and uniplanar configuration. This paper presents a novel, high gain and miniaturized rectangular dielectric resonator antenna using a metallic slab as a loading element, integrated with the CPW feed. The rectangular DRA is fed with a CPW (Capacitive type) feed to ensure efficient coupling. The unloaded and loaded DRA resonance frequencies are 4.55 GHz and 3.80 GHz respectively, achieving a 16.48% reduction in resonance frequency. The gain of the unloaded and the loaded DRAs are 6.34 dBi and 6.95 dBi respectively. As a result, a 8.77% increase in gain is obtained with the loaded configuration. In addition, despite the high reduction in resonance frequency and conductor loading, it is observed that there is no significant change in efficiency of the loaded antenna relative to the original structure. Also, it is seen that the coupling performance, cross-polarization and front-to-back ratio in the radiated fields of the size-reduced antenna remain essentially unchanged relative to the unloaded configuration. View full abstract»

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  • Broadband reactively coupled ring microstrip antenna

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (305 KB) |  | HTML iconHTML  

    The broadband rectangular microstrip antennas are realized by using multi-resonator gap-coupled and stacked configurations. However they increase the size of the configuration in either vertical or horizontal directions. By cutting the resonant slots inside the patch the bandwidth is increased without increasing the total patch size. By using the different feed technique like L-probe feed the bandwidth of the antenna is increased. In this paper, the broadband Rectangular microstrip antenna and square ring microstrip antenna by using the reactive coupling through the rectangular coupling strip are proposed. These antennas give broader bandwidth with broadside radiation pattern with gain of more than 6 dBi over the complete operating bandwidth. View full abstract»

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  • Multi-band stub loaded square ring microstrip antennas

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (350 KB) |  | HTML iconHTML  

    The square ring microstrip antenna is a compact variation of square microstrip antenna and it is realized by cutting the slot in the center of the patch. The multi-band microstrip antenna is realized by placing the open circuit stub on the edges of the patch. The stub offers capacitive or inductive impedance around the resonance frequency of the patch and realizes dual frequencies. In this paper, the multi-band frequency response of the stub loaded square ring microstrip antennas is studied. Also the multi-port network model for these antennas is proposed, which helps in analyzing the voltage distributions at various frequencies. These voltage distributions are in good agreement with the current distributions generated using the IE3D software. View full abstract»

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  • CAD model to compute the resonant frequency of an equilateral triangular microstrip patch antenna including radome effect

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1532 KB) |  | HTML iconHTML  

    Shifting of resonant frequency due to dielectric radome of a triangular microstrip antenna is theoretically investigated. A very simple, more accurate and more efficient CAD model is proposed in this paper. The computed values for wide range of variations of superstrate thickness and dielectric constant are compared with different theoretical and experimental values available in open literature and revealed close agreement. View full abstract»

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  • Capacitive fed Coplanar waveguide slot antenna for RFID applications

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    In this paper capacitive fed Coplanar waveguide slot antenna is proposed for RFID applications. The fundamental parameters of the antenna such as bandwidth, return loss, gain, radiation pattern and polarization are obtained. All meets the acceptable antenna standards. Simulation tool, based on the method of moments (ZELAND IE3D version 12.0) has been used to analyze and optimize the proposed antenna. View full abstract»

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  • Simplified and efficient technique for designing of broadband patch antenna

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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1421 KB) |  | HTML iconHTML  

    In high-performance aircraft, spacecraft, satellite, and missile applications, where size, weight, cost, performance, ease of installation, and aerodynamic profile are constraints, and low-profile antennas may be required. Presently there are many other government and commercial applications, such as mobile radio and wireless communications that have similar specifications. To meet these requirements, microstrip antennas can be used. This paper presents a novel technique for design and development of a broadband patch antenna by loading reactively with slots placed in such a manner it closely resembles an E shape for various applications in wireless communications. The antenna was designed for operating in S band (2.0 - 2.3 GHz) frequency range with a linear polarization and it was built as E shaped patch antenna. The feeding arrangement in the presented experimental models above is a coaxial connector in the ground plane with the center-pin extended to the patch as an inductive probe although other feeding methods could be easily adapted. The developed antenna successfully attains a bandwidth of 18% (VSWR <2) with a central frequency of 2.03 GHz. Also it attains an acceptable value of gain of about 6.3 dB with respect to its central frequency .The measured 3 dB Beamwidth is of about 83.62?? and 96.03?? in E-plane and H- plane respectively. The designed antenna was successfully developed and tested in anechoic chamber. View full abstract»

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  • Perturbed hexagonal microstrip antenna for circular polarization

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    Hexagonal microstrip antenna with perturbed edges and a single coaxial feed has been proposed for circular polarization. The configuration has been realized by inserting perturbations along two opposite sides of the hexagonal microstrip antenna. Both left-hand and right-hand circular polarization is obtained, simply by displacing the feed location by 90 degree. The measured bandwidth corresponding to VSWR ?? 2 of 26.2 MHz and the 3 dB axial ratio bandwidth of 6.01 MHz has been achieved for the antenna which is designed at 915 MHz. Theoretical results have been validated with experiments. View full abstract»

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