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Monopole Antennas (monopole + antennas)
Selected AbstractsModeling and optimization of cylindrical antennas using the mode-expansion method and genetic algorithmsINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 6 2005Dawei Shen Abstract For monopole antennas with cylindrically symmetric structures, a mode-expansion method is highly time efficient, which is a realistic approach for integrating function-optimization tools, such as genetic algorithms (GAs), in order to extract the best bandwidth property. In this article, a mode-expansion method is used to simulate the impedance characteristics of the cylindrical antennas. As examples, two new types of monopole antennas are presented, one of which possesses a two-step top-hat structure while the other has an annulus around the stem. After the modeling scheme is examined for convergence and data validity, the associated optimization problem, with dimensions as decision variables, structural limitations as linear constraints, and desired bandwidth performance as an objective function, is solved using GAs. The effects of the geometric parameters on the impedance characteristics are investigated in order to demonstrate the optimality of the calculated solutions. Two optimized practical antennas are designed based on our numerical studies. One has a broad bandwidth of 3 GHz while the other shows a dual-band property, which can satisfy the bandwidth requirements for both Bluetooth (2.45-GHz band) and WLAN (5-GHz band) systems. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [source] High-gain, short-circuited six-monopole-antenna system for concurrent, dual-band WLAN access pointsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010Saou-Wen Su Abstract A high-gain, short-circuited multimonopole antenna system for wireless access points in the concurrent 2.4 and 5 GHz WLAN bands is presented. The antenna system mainly comprises a circular antenna ground and six short-circuited, single-band monopole antennas, among which the three antennas are designated for 2.4 and 5 GHz operation respectively. The monopole antennas are set in a sequential, rotating arrangement on the antenna ground, and the 2.4 and 5 GHz antennas are facing each other one by one. Experimental results show that well port isolation can be obtained between the antenna ports with high-gain properties over the 2.4 and 5 GHz bands. A design prototype is elaborated and discussed in the article. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2728,2732, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25588 [source] Planar ultrawideband antenna array for short-range wireless communicationsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2010Osama M. H. Ahmed Abstract In this article, novel 2-element and 4-element planar ultrawideband (UWB) antenna arrays with bidirectional radiation patterns based on identical UWB antenna elements for UWB communications applications have been proposed, simulated and experimentally investigated. Each array is constructed by means of feeding omni-directional printed UWB monopole antennas with a UWB power divider. The proposed 2-element antenna array yields an impedance bandwidth of 110% (3.1,10.6 GHz) covering the whole UWB frequency bandwidth while the impedance bandwidth is multi-band in case of the 4-element antenna array because of the increasing effect of mutual coupling among antenna elements. The calculated gain of the 2-element and 4-element array is quite stable with about 3 and 6 dB higher than that of the single element, respectively. Both measured and calculated E-plane radiation patterns of the array and the single element are almost the same while the H-plane radiation patterns of the array are distinctively bidirectional compared to the omni-directional pattern of the single element. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1061,1066, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25140 [source] Integration of internal 700 MHz and WLAN/WiMAX antennas for palm-sized mobile devicesMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2008Jui-Hung Chou Abstract Two promising, internal, shorted monopole antennas for 700 MHz and WLAN/WiMAX operation are combined in an arrangement with minimized mutual coupling for palm-sized mobile applications. The two stamped, metal-plate antennas with a 2-mm gap therein between can be integrated into a compact configuration and are then mounted near one side of the system circuit board. With the suitable shorting locations and arrangement of the two antennas, good isolation (S21 < ,20 dB) between the two ports can easily be obtained. Analysis of placing a CCD shielding cylinder between the two antennas and the two shorting strips joined to form a shorting wall are also conducted. Detailed designs of the two antennas are described, and the results thereof are discussed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2948,2951, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23833 [source] Printed inset sleeve monopole antennas for dual-band applicationsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2008J.-W. Baik Abstract In this study, the simple printed monopole antennas with dual-band operation are presented. The proposed antennas without any additional metal strips are consisted of the ground shorted inset sleeve for both microstrip and coplanar waveguide type ones. The omnidirectional radiation patterns of two models at two designed frequencies are almost similar to those of a conventional monopole. These printed monopole antennas are very suitable to various dual-band applications for modern communications. Details of the proposed design and experimental results are demonstrated in this article. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1995,1997, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23574 [source] Compact-planar monopole loop antennas for 802.11b/g WLAN systemsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2007Mariusz Bledowski Abstract Two monopole antennas using Koch loop and Minkowski loop radiators fed by microstrip line are proposed for WLAN applications in the 2.45/5.25 bands. To achieve the desired resonances, new configurations of impedance transformer with transmission line length close to ,/12 were designed. The prototypes have been examined, fabricated, and experimentally tested and found to fulfill with excess WLAN system requirements. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2299,2303, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22720 [source] A method to optimize the bandwidth of UWB planar monopole antennasMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2006D. Valderas Abstract This paper describes a method to optimize a planar hexagonal monopole antenna (PHMA) for ultra-wideband (UWB) applications. In the Smith chart, a design process is followed to improve the broadband matching of a fixed lower-frequency-limit rectangular monopole by a suitable geometry for the lower edge and monopole width. A prototype is simulated, constructed, and tested. As a result of the design, the achieved impedance bandwidth is larger than 1:37 (VSWR < 2). The radiation characteristics are also discussed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 155,159, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21291 [source] Some design criteria for UWB planar monopole antennas: Application to a slotted rectangular monopoleMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2005D. Valderas Abstract A method to increase the bandwidth of planar monopoles is presented. Following the provided design criteria, a simple rectangular-shaped monopole is fit to operate at ultra-wide-band (UWB) frequency. The process involves two steps: (i) optimizing the perimeter and feeding dimensions and (ii) conducting a suitable slot. This causes the difference between the upper and lower frequency limits to nearly double. The exhibited bandwidth ratio is 1:3.75. The measured radiation patterns are presented and observed to be stable. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 6,11, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20885 [source] Control of the impedance bandwidth of wideband planar monopole antennas using a beveling techniqueMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2001M. J. Ammann Abstract Wideband planar monopole antennas have recently been proposed for use on digital mobile terminals. The square planar monopole is the simplest to analyze, and suffers little degradation of radiation pattern within the impedance bandwidth. The addition of a bevel on one or both sides of the feed probe is shown to increase the bandwidth with good control of the upper edge frequency. The impedance bandwidth ratio for this antenna is shown to vary from 2:1 to 6:1, which can be controlled by beveling the planar geometry. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 229,232, 2001. [source] | ||||||||||