Radiation Patterns (radiation + pattern)

Distribution by Scientific Domains


Selected Abstracts


Analysis of V-slot loaded patch for wide-band operation

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2008
J. A. Ansari
Abstract In this article, analysis of V-slot loaded patch antenna is proposed using equivalent circuit model. Such antenna provides a wide bandwidth which depends inversely on the base width and slot thickness. The proposed results are compared with experimental and simulated results which are in good agreements. Radiation pattern of the proposed antenna is in good agreement with the simulated results. This validates the accuracy of the proposed model. 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3069,3075, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23891 [source]


A compact pentagonal monopole antenna for portable UWB systems

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010
Paulbert Thomas
Abstract Design of a compact microstrip-fed ultra-wideband antenna suitable for USB dongle and other such space constraint applications is presented. The structure consists of a pentagonal monopole element and a modified ground plane that gives an impedance bandwidth from 2.8 to 12 GHz. Radiation patterns are stable and omni-directional throughout the band with an average gain of 2.84 dBi. The antenna occupies only 11 30 mm2 on FR4 substrate with permittivity 4.4. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2390,2393, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25449 [source]


Controlled sources for shear-wave surveys in mines

GEOPHYSICAL PROSPECTING, Issue 3 2000
Gordon M. Holmes
The ability to analyse shear-wave anisotropy in a mine environment is greatly aided by using multiple source orientations of a reproducible, impulsive shear-wave source. The analysis of what is probably the first controlled source shear-wave experiment in a mine environment demonstrates clearly that shear-wave polarizations and time delays between split shear-wave arrivals are reliably measured because of the use of multiple source orientations rather than a single shear-wave source. Reliability is further aided by modelling the shear-wave source radiation pattern, which allows for the unequivocal discrimination between seismic raypaths where shear-wave splitting did and did not occur. The analysis also demonstrates the great importance of high reproducibility of the seismic source for the use of shear waves in time-lapse surveys to monitor changes in a rockmass. [source]


A method of accurate determination of azimuthal distribution of received RF power

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 2 2001
A. A. Alexandridis
Abstract In this paper, we introduce a method for the determination of directional distribution of received RF power, with angular resolution independent of receiving antenna radiation pattern. The proposed method is based on a series of measurements taken while rotating, at fixed predefined steps, a usual directional antenna of known radiation pattern on the azimuthal plain. It is proved that the resolution accuracy of the measurement method depends only on the angular step of the antenna rotation and it is independent of the antenna beamwidth. As a result of this feature, the proposed method allows the determination of the RF power angular distribution with fine resolution using a directional antenna of much wider beamwidth for the measurements. Copyright 2001 John Wiley & Sons, Ltd. [source]


Sleeve monopole on a circular ground-plane

INTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5 2003
Zhongxiang Shen
Abstract This paper presents a modal-expansion analysis of a sleeve monopole antenna on a finite ground-plane. Two perfectly conducting plates (one above the monopole and the other under the ground-plane) are introduced to confine the modeling region and to facilitate the modal-expansion analysis. The resulting guided-wave structure is then divided into a number of regions and the electromagnetic field components in each region are expanded into the summation of its modal functions. The surface current distribution on the monopole and the antenna's input impedance and radiation pattern are obtained by finding the expansion coefficients through matching the tangential field components across the regional interfaces. Calculated results by the modal-expansion method agree well with measured results for the return loss of a sleeve monopole fed through a circular ground-plane by a coaxial probe. Numerical results for the surface current distribution, input impedance, and radiation pattern of a sleeve monopole on a circular ground plane are presented and discussed. Copyright 2003 John Wiley & Sons, Ltd. [source]


Design of a linear array antenna for shaped beam using genetic algorithm

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2008
Sona O. Kundukulam
Abstract A linear array antenna design with desired radiation pattern has been presented based on genetic algorithm (GA) approach. Examples of cosecant and flat-topped beam patterns are illustrated to show the flexibility of GA to solve complex antenna synthesis problems by suitably selecting the fitness function, even with a simple GA. The results have been validated by IE3D electromagnetic simulation. The antenna arrays with different element geometries can also be implemented using the proposed technique. 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008. [source]


A high-gain dual-band directional/omnidirectional reconfigurable antenna for WLAN systems

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 3 2008
Min Ding
Abstract A high-gain dual-band antenna for the wireless local area network system is presented in this article. Two symmetrical linear arrays can be dynamically reconfigured that could switch radiation pattern with a switchable feed circuit between direction and omnidirection. The antenna can also be used for a pattern diversity antenna for the multiple-input,multiple-output communication systems. The design process for the antenna system is given, and the parameters and characteristics of the antennas are achieved by the method. Measured return losses, isolation, and radiation patterns are in good agreement with the simulated ones, which illustrates that the method is valid and the antenna system can be integrated with pattern reconfigurable and pattern diversity applications. 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008. [source]


Characteristic analysis of reverse-L-shaped microstrip-fed large-bandwidth printed slot antenna

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 6 2002
Yong-Woong Jang
Abstract The characteristics of a reverse-L-shaped microstrip-fed structure is analyzed using the finite difference time domain method, and the characteristics of the proposed antenna are compared with a conventional antenna. The return loss, radiation resistance, and voltage,standing wave ratio in the frequency domain are calculated by Fourier transforming the time domain results. When the proposed feed structure is used, the bandwidth is extended in proportion to the slot width and the radiation resistance has the low value. When the slot width is 16 mm, the experimental bandwidth is approximately 50% (,10 dB , S11) at the center frequency of 2.3 GHz. In addition, the experimental data for the impedance and radiation pattern of the antenna are described. They are in good agreement with the calculated results. 2002 Wiley Periodicals, Inc. Int J RF and Microwave CAE 12, 496,502, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mmce.10055 [source]


Single elements for low cost planar antenna arrays for consumer applications beyond 100 GHz

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010
Pablo Herrero
Abstract Single planar element designs working at frequencies around 122 GHz are presented. The structures are designed keeping in mind future commercial applications that might arise in mm-wave bands. Therefore, structures are explored with different radiation patterns. The antennas are implemented using commercial substrate and common photolithography to meet low cost requirements of consumer applications. Matching and radiation pattern was measured showing very good agreement simulations. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2685,2688, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25563 [source]


A novel miniature monopole tag antenna for passive UHF RFID applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2010
Hsien-Wen Liu
Abstract A novel miniature monopole tag antenna for passive Ultra-High Frequency (UHF) radio frequency identification (RFID) operation is presented. The antenna possesses a two-sided structure that is printed on an FR4 substrate and fed by a 50-, microstrip line. By properly using helical strips and vias, the antenna size can be reduced to a small volume of 10 (L) 9.5 (W) 0.8 (H) mm3 to be easily integrated within various portable devices. A miniaturized quasi-lumped circuit is also designed to attain a good impedance matching between the antenna and the chip. Experimental results demonstrate that the antenna has a suitable operating band about 914,939 MHz and also quite omnidirectional radiation pattern with appreciable gain. Moreover, the proposed compact tag antenna, capable of achieving a maximum readable range of about 5.6 m with an EIRP equal to 4 W, is well suited for RFID applications. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2770,2772, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25596 [source]


Compact top-loaded ultra-wideband biconical antenna for indoor base-station applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2010
W. J. Lu
Abstract A biconical antenna employing the top-loaded technique is proposed for ultra-band (UWB) operation. The antenna is composed of a small cone mounted on a top-loaded disc and a conical ground plane, with both cones electrically connected together using four shorting pins to reduce the lower cutoff frequency. The antenna is investigated using computer simulation and measurement. Results show that the antenna has an impedance bandwidth from 0.8 GHz to over 11.2 GHz, dipole-like omnidirectional radiation pattern, average gain of about 4.2 dBi, and average radiation efficiency of over 88%. The antenna has the advantageous features of compact size, low profile, simple structure, and ultra-wideband characteristic and so is suitable for indoor base-station applications of many existing and future wireless and UWB systems. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2594,2598, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25540 [source]


A novel compact CPW-fed planar monopole antenna with modified stair-style ground for ultra-wideband applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2010
Y.-B. Yang
Abstract In this article, a simple and compact CPW-fed planar monopole antenna for ultra-wideband applications is presented and investigated. The proposed antenna with a small size of 26 mm 26 mm 1 mm is composed of a gourd-like radiation element fed by a CPW feed line, and a modified stair-style ground. The proposed antenna has been successfully designed, fabricated, and measured. The measured results show that the antenna achieves a wide impendence bandwidth from 3.1 to 15.2 GHz with return loss less than ,10 dB. In addition, it exhibits a nearly omnidirectional radiation pattern, stable antenna gain, and good time-domain characteristics across the operation band. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2100,2104, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25378 [source]


A novel dual-band square piece patch antenna for wireless applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2010
T. Shanmuganantham
Abstract A novel dual-band square microstrip patch antenna for bandwidth improvement and antenna size reduction in a single design is proposed. It can operate at dual frequencies of 1.7 GHz and 5.5 GHz. The fundamental parameters of the antenna such as bandwidth, return loss, gain, radiation pattern, and polarization are obtained. This square piece patch antenna has less return loss of ,40 dB with bandwidth of 40 MHz and 200 MHz in two bands, respectively. The sensitivity of patch antenna towards its patch shape is also discussed. Simulation tool, based on the method of moments (ZELAND IE3D version 12.0) has been used to analyze and optimize the antenna. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1513,1516, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25270 [source]


L-strip proximity fed shorted rectangular microstrip antenna for mobile communication

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2010
Amit Kumar Singh
Abstract A dual-band L-strip proximity fed shorted rectangular microstrip antenna is proposed and investigated theoretically simulated by HFSS and experimentally. Proposed radiating patch is located about (17.5 mm) above the ground plane. Return Loss and co- and cross polar radiation pattern are presented. Computed and measured results of return loss are in good agreement. The effect of the geometric parameters of the proposed antenna, such as length of the vertical and horizontal portion of the L-strip is also investigated. The impedance bandwidth (,10 dB return loss) 32.5% (calculated) and 33.00% (measured) for the proposed antenna are achieved for optimized antenna design. Significant size reduction (i.e., ,85%) is obtained as compared with conventional rectangular patch of same resonant frequency. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1567,1571, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25235 [source]


An inkjet-printed inverted-F antenna for 2.4-GHz wrist applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2009
Vamsi K. Palukuru
Abstract In this article, an inkjet-printed inverted-F antenna suitable for a watch-type wireless communication device is presented. The antenna and covering the 2.4 WLAN band (2.4,2.484 GHz) has thickness (2 mm3) and size (40 25 mm2). The performance of the printed antenna is experimentally studied and compared with a reference antenna made of Rogers copper laminate. The effect of inkjet-printed layer thickness on the antenna performance is presented. In addition, the impact of the user's hand proximity on the antenna performance is studied experimentally. The results showed that the total antenna efficiency increases by 13% and 27% with an increase of 1.5 ,m in printed layer thickness and a user's hand to antenna distance of 12.5 mm, respectively. The shape of the radiation pattern of the antenna is distorted due to the proximity of the user's hand. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2936,2938, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24777 [source]


Vertically meander-folded, shorted-patch antennas

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2009
Alois Holub
Abstract In this study, a novel miniaturized microstrip patch antenna based on meander-folded, shorted-patch (SP) structure is introduced. The technique enables a decrease of the original quarter-wavelength patch length approximately by the factor 1/N, where N is the number of the vertically placed patch plates above the ground plane. The antenna operational principle is explained with the help of E-field distribution and can be interpreted as SP with vertically meander-folded cavity. Further modification of the top patch plate to ensure symmetrical radiation pattern is proposed. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2938,2942, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24790 [source]


Center-fed circular Epsilon-negative zeroth-order resonator antenna

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2009
Hangfei Tang
Abstract A center-fed circular ,-negative zeroth-order resonator antenna with a symmetrical omnidirectional radiation pattern is investigated numerically and experimentally in this article. The radiation pattern of the proposed antenna is symmetrical. Furthermore, symmetry of radiation pattern, bandwidth and gain could be improved by adding unit-cells and adjusting unit-cell parameters. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2423,2428, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24639 [source]


Design of dual-band antenna with U-shaped open stub for WLAN/UWB applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009
Jung N. Lee
Abstract In this article, we have proposed a dual-band antenna with U-shaped open stub for wideband local area network (WLAN)/ultra wideband (UWB) applications. The designed dual-band antenna consists of two semicircle radiating patches, a rectangular slot separating the two semicircles, one step for impedance matching, and coplanar waveguide (CPW) feeding. Two kinds of prototypes (CPW-fed UWB antenna and the dual-band antenna with U-shaped open stub) are fabricated and measured. Parametric studies and radiation characteristics for the two antennas are presented. The designed antenna has the figure-of-eight radiation pattern, wide bandwidth, and negligible dispersion over the operating frequency band. 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 284,289, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24033 [source]


Compact multiband slotted antenna for wireless communication applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2009
Yi-Chieh Lee
Abstract New design of a compact antenna with slotted structure for multioperating bands of wireless communication systems is presented. By using compact configuration and slot designs on printed circuit board, the proposed antenna has the multiband measured operations for covering the 2.4-GHz WLAN (2.4,2.484 GHz), the WiMAX (IEEE 802.16e in the Taiwan: 2.5,2.69/3.5,3.65 GHz), and the 5-GHz WLAN (5.15,5.35/5.725,5.825 GHz) bands. Several properties of the proposed compact antenna for multiband operation such as impedance bandwidth, radiation pattern, and measured gain have been numerically and experimentally investigated. 2008 Wiley Periodcals, Inc. Microwave Opt Technol Lett 51: 502,503, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24094 [source]


A novel ultra-wideband monopole antenna with two symmetrical strips

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2008
Hyo W. Song
Abstract In this article, we have described a novel ultra-wideband (UWB) monopole antenna with two symmetrical strips for wireless UWB communications. The proposed antenna consists of a center monopole, two symmetrical strips having one step on the strip, and CPW feeding. Three techniques (one monopole and two strips, symmetrical structure, and step on the strip) are used to produce the multiple resonance and low dispersion. The proposed UWB antenna has an omnidirectional radiation pattern, UWB, compact size, almost flat gain and linear phase, and low cost. 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2845,2848, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23838 [source]


The design and performance analysis of integrated amplifier patch antenna

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2008
Adnan Kaya
Abstract This work presents the design of an active amplifier antenna. Active integrated antennas can be obtained with active components directly connected to the antenna structure. In this article, a novel active integrated single microstrip antenna analysis and its radiation pattern and gain performance is proposed. A high-efficiency, low noise, and high linear compact amplifier integrated with a microstrip antenna at 1.6 GHz is presented for RF front-end circuit applications. The design in this study consists of a rectangular microstrip antenna with a pair of parallel slots loaded close to the radiating edge of the patch and three meandering narrow slots embedded in the antenna surface. With the proposed design a size reduction of 34% for the 1.6- and 2.6-GHz resonant frequencies is obtained and the two frequencies have an operation frequency ratio of 1.30. In this design approach, the measured antenna impedance is transformed with matching to the load impedance for maximum efficiency. With the proposed amplifier antenna design, the antenna radiation pattern can be better than an antenna radiation pattern without matching. In addition, it has been shown that compensation significantly improves the return loss matching level. 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2732,2736, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23765 [source]


5.8 GHz orientation-specific extruded-fin heatsink antennas for 3D RF system integration

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 7 2008
Lance Covert
Abstract In high-power RF transmitter applications, the heatsink can be used as an antenna for improved antenna performance and increased integration. Extruded-fin heatsink antennas designed at 5.8 GHz are orientation-specific when the heatsink base replaces the patch of a patch antenna. In this case, the orientation of the fins with respect to the patch edges plays a significant role in the antenna performance and must be considered. The results show that the heatsink antenna using a lossy, low-cost FR4 substrate increases the bandwidth from 3.1 to 17.6% and radiation efficiency from 62 to 87% compared with the patch antenna on the same substrate. Also, the orientation has a significant effect on the directivity, gain, and radiation pattern. By combining two functions into one structure, the component count in a system is reduced and the antenna performance can be improved. Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1826,1831, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23478 [source]


Circular fractal monopole antenna based on descartes circle theorem for UWB application

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2008
Salman Naeem Khan
Abstract An apollonian shaped ultra-wideband circular monopole antenna based on descartes circle theorem is presented. Different self similar geometries from DCT are analyzed and optimized for UWB applications. The proposed design is slightly modified to ensure an overall smooth current distribution limited by the junction point nature of the fractal geometries. The experimental results are compared with conventional circular disk monopole and annular monopole antenna. The measured return loss of the proposed design below ,10 dB is from 2.4 to over 40 GHz and its radiation pattern is omni-directional compared with circular disk and annular antennas in most of its impedance bandwidth. Moreover due to the fractal shape, the proposed design has less weight and wind loading effect. 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1605,1608, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23437 [source]


Decorrelation of two closely spaced antennas with a metamaterial AMC surface

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2008
P. J. Ferrer
Abstract A metamaterial spacer to decorrelate two closely spaced antennas has been designed and tested. The metamaterial spacer exhibits an artificial magnetic conductor (AMC) behavior around 2.6 GHz. Its performance has been checked against a simple metal spacer (PEC), providing a quasi orthogonal radiation pattern and good results in terms of decoupling and decorrelating a two-antenna system. 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1414,1417, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23365 [source]


A compact spiral stripline-loaded monopole antenna with a vertical ground plane

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2008
Truong Khang Nguyen
Abstract In this letter, we propose a compact spiral stripline-loaded monopole antenna on a vertical ground plane. The measured results show that the antenna has a fractional bandwidth of 12.1% for a voltage standing wave ratio (VSWR) less than 2 at the center frequency of 1.10 GHz, as well as a good omni-directional radiation pattern. The small size of 0.04 ,o 0.04 ,o 0.04 ,o makes it promising for use as an internal antenna in mobile handsets. 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 250,252, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23043 [source]


A wideband 8-element omnidirectional array for wireless system

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2007
Dakui Wu
Abstract A smart broad-band planar antenna for wireless system is presented. The simple modeling of this antenna and design method based on equivalent circuits has been developed. An eight-element planar array has been designed, fabricated and measured. Measured results exhibit good performance of the return loss and horizontal plane radiation pattern. The measured 10-dB return loss bandwidth of the broad-band planar array is demonstrated to be 62.5% and the un-roundness of its horizontal plane pattern is less than 4.5 dB. 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2944,2946, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22925 [source]


Compact printed semi-elliptical monopole antenna for super-wideband applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2007
Xiao-Rong Yan
Abstract A compact semi-elliptical patch antenna fed by a tapered coplanar waveguide is introduced for super-wideband (SWB) applications. The simulated and experimental results demonstrate that the antenna possesses the desirable SWB characteristics, achieving a ratio bandwidth of 19.7:1 for VSWR , 2, and exhibits a nearly omni-directional radiation pattern, while its area is only about 0.15,l 0.21,l, where ,l is the wavelength of the lowest operating frequency. 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2061,2063, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22644 [source]


A dual-band antenna design for GPS and UMTS applications

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2007
Chow-Yen-Desmond Sim
Abstract The design of an integrated dual-band antenna for global positioning system (GPS) and universal mobile telecommunications system (UMTS) is presented. A circularly polarized square-ring corner truncated microstrip antenna is designed for GPS application, and a monopolar shorted square patch antenna embedded within the center of the square-ring is designed for UMTS application. Both proposed antenna elements demonstrated desirable isolation, radiation pattern; polarization, and bandwidth requirement. 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1935,1939, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22597 [source]


Spiral antenna with helix loaded for dual circularly polarized bands radiation

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 8 2007
Can-Hui Chen
Abstract A spiral antenna with a helix loaded is investigated in this paper. Through combining the spiral with a helix together, circular polarization can be achieved in dual bands. Since the helix is loaded in the lower part of the spiral, this technique doesn't increase the antenna's volume but at the same time introduces another CP band. The experimental result shows that the lower band and upper band are 4.0% and 62.07% respectively. The characteristics of impedance, current distribution and radiation pattern will also be presented. 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1939,1942, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22596 [source]


Meandering probe fed patch antenna with high gain characteristic for circularly polarized application

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2007
Hau-Wah Lai
Abstract A meandering probe-fed circularly polarized stacked patch antenna with truncated corners is studied. The antenna has a wide 3-dB axial ratio bandwidth of 12%. It exhibits a stable radiation pattern across the axial ratio bandwidth. The antenna has low cross polarization and high gain, which are ,14 dB and 10 dBi, respectively. 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1095,1098, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22357 [source]