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ABSTRACT: A wideband omnidirectional and compact (WIBOC) antenna is proposed in this letter. The antenna is constructed with a combination of an upper metallic plane with an elliptic shape, a rectangular metallic plane placed underneath, and a discone monopole antenna used as an excitator located between these metallic planes. This antenna provides broadband characteristics and omnidirectionnal radiation patterns in the azimuth plane over the whole bandwidth with a height limited to λ<sub>LF</sub>/29, where λ<sub>LF</sub> is the lowest frequency of the operating band.
IEEE Antennas and Wireless Propagation Letters 02/2011; · 1.37 Impact Factor
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ABSTRACT: A wideband high efficiency 60 GHz aperture superstrate antenna is studied and characterized. It is found by measurement that, using superstrate above aperture antenna we can improve the gain up to 13.1 dBi with a wide bandwidth of 15%. The estimated efficiency is 79%. This good results is higher than that of a classical 2x2 array, on RT Duroid substrate, with a gain of 12 dBi and an efficiency of 60%. Also this antenna has wide bandwidth and efficiency compared to the superstrate antenna. The implementation of this antenna is simple and the size of the antenna is smaller. In conclusion, for wideband and high gain high efficient antenna applications, aperture antenna with superstrate is one solution for 60 GHz indoor systems.
Antennas and Propagation Society International Symposium (APSURSI), 2010 IEEE; 08/2010
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ABSTRACT: This article presents a new reflection-type 360° phase shifter, for Ku- and Ka-bands applications.At 12 GHz, the measured prototype has more than 360° phase shift with insertion loss of 3.3 ± 0.5 dB. For the Ka-band circuit, the lowest insertion loss is obtained at 30.3 GHz (3.6 dB ± 1.8 dB) and the phase shift is 315°. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1733–1736, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25307
Microwave and Optical Technology Letters 05/2010; 52(8):1733 - 1736. · 0.62 Impact Factor
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ABSTRACT: In this study, a technology based on a meshed silver/titanium bilayer printed on glass substrate is briefly presented. Three transparent monopole antennas made from such a material show sheet resistances and optical transparencies ranging from 0.014 Ω/sq to 0.054 Ω/sq and from 56.3% to 81.3% respectively. We investigate the performances of these transparent monopole antennas. Experimental S 11 and gains are compared with those of a reference antenna fabricated from a light reflecting silver/titanium film. Transparent antennas provide radiation efficiency better than 85%.
Antennas and Propagation (EuCAP), 2010 Proceedings of the Fourth European Conference on; 05/2010
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03/2010; , ISBN: 978-953-7619-67-1
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ABSTRACT: This article presents a Ku band 360° analogue phase shifter optimized with a genetic algorithm. Varactor diodes are used as the tuning elements. The device presents 360° phase shift on 11% bandwidth. At 12 GHz, the insertion loss is found to be −2.2 ± 0.4 dB. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 283–285, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24944
Microwave and Optical Technology Letters 12/2009; 52(2):283 - 285. · 0.62 Impact Factor
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ABSTRACT: A frequency tunable antenna made with an open-circuit monopole coupled loop antenna associated to a varactor diode is presented. The proposed antenna shows a 35.8% relative bandwidth, covering the 470-675 MHz frequency range. Theoretical and experimental results of S <sub>11</sub>, radiation patterns and gain have been performed and show good agreement.
Electronics Letters 12/2009; · 0.96 Impact Factor
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ABSTRACT: A technology based on a meshed silver/titanium bilayer printed on glass substrate is briefly presented. A sheet resistance equal to 0.054 /sq with 81.3 of optical transparency is obtained. The performances of a monopole antenna made from such a material have been investigated. The measured S<sub>11</sub> and gain of the transparent antenna are compared with those of an antenna fabricated from a reflective silver/titanium film, and stand for reference. The transparent antenna provides radiation efficiency better than 85%.
Electronics Letters 10/2009; · 0.96 Impact Factor
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ABSTRACT: An easy-to-implement procedure for antenna test facility axis check up has been presented. This procedure based on antenna measurements has been validated with measurements performed in the V-band. Tilts on azimuth axis and roll axis have been determined with an uncertainties of 0.05deg. Compensation of these tilts have been applied to determine as well the antenna under test tilt and their comparison to reference values show good results.
Antennas and Propagation, 2009. EuCAP 2009. 3rd European Conference on; 04/2009
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ABSTRACT: The general issue of this paper deals with the design of a phased array antenna for high data rate SATCOM on UAV (Unmanned Aerial Vehicle) in Ka band. This paper presents: 1) a comparative study of possible antenna element candidates for a 30 GHz circularly polarized and wide angle scan phased array. 2) a new low loss analog phase shifter concept. This will lead to the conception of a phased array antenna and also of phase shifters.
Antennas and Propagation, 2009. EuCAP 2009. 3rd European Conference on; 04/2009
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ABSTRACT: Thanks to ACE 2 umbrella, measurement cooperation between IETR and TKK-MilliLab has been established and thus enabling characterization of a half Maxwell fish eye lens at 150 GHz. Results at 110 GHz provide comparison between IETR and TKK-MilliLab antenna test facilities. The agreement between the results is very good. Results at 150 GHz provide the first information for future development of such lens in the G-band.
Antennas and Propagation, 2009. EuCAP 2009. 3rd European Conference on; 04/2009
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ABSTRACT: This paper presents two compact wideband omnidirectional antennas for applications in the VHF and UHF bands. These antennas are based on new shapes which allow a reduction of the height of the monopole without any deterioration of the radiation properties over at least one octave bandwidth.
Antennas and Propagation, 2009. EuCAP 2009. 3rd European Conference on; 04/2009
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ABSTRACT: The impact of polarization on the distribution of the above ground surface (AGS) electric field is presented for vehicular applications. It is demonstrated that the homogenization of the E-field components, directly over the ground, can be optimized by a judicious choice of polarization. Simulations and measurements demonstrate these results.
Antennas and Propagation, 2009. EuCAP 2009. 3rd European Conference on; 04/2009
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ABSTRACT: This paper deals with radiation pattern reconfigurable antenna in millimetre wave range. The innovative antenna system is based on an inhomogeneous HMFE lens (Half Maxwell Fish Eye) fed by sources array. The number of fed sources and the lens allow to both control the radiation pattern and to achieve a good efficiency. The global antenna permits to have beam shaping capability without phase shifters. Directive and sectorial radiation patterns can be obtained for both on-axis and off-axis configurations.
Antennas and Propagation, 2009. EuCAP 2009. 3rd European Conference on; 04/2009
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02/2009: pages 163 - 232; , ISBN: 9780470742969
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ABSTRACT: A high-efficient and high-gain aperture coupled patch antenna with superstrate at 60 GHz is studied and presented. It is noted that adding superstrate will result in a significant effect on the antenna performances, and the size of the superstrate is critical for the optimum performance. The maximum measured gain of a single antenna with superstrate is 14.6 dBi, which is higher than that of a classical 2 x 2 array. It is found that the gain measured of a single antenna with superstrate increases nearly 9 dB at 60 GHz over its basic patch antenna. This superstrate antenna gives a very high estimated efficiency of 76%. The 2:1 measured VSWR bandwidth with superstrate is 6.8%. The radiation patterns are found to be broadside all over the frequency band. Also, this letter explains a comparison to another source of parasitic patch superstrate antenna with normal microstrip coupling. It is found that aperture coupling is better for high-gain antenna applications.
IEEE Antennas and Wireless Propagation Letters 02/2009; · 1.37 Impact Factor
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ABSTRACT: A monopole coupled loop antenna (MCLA) is studied and modified. The modification includes reducing the size of the antenna and its radiating properties in order to obtain quasi-unidirectional radiation pattern for mobile communications. An analysis of the surface current distribution has been performed to explain this phenomenon. The theoretical results have been validated with measurements.
IEEE Antennas and Wireless Propagation Letters 02/2009; · 1.37 Impact Factor
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ABSTRACT: Equivalent circuit modeling methodology is proposed in this letter for a small broadband antenna composed of a conical monopole with metallic parasitic elements, a capacitive disk, and a dielectric substrate around the feed region. This omnidirectional antenna provides broadband performances over the whole bandwidth with a height limited to a one-eighth wavelength associated to the lowest frequency. The proposed modeling procedure presents excellent agreement with electromagnetic and experimental results.
IEEE Antennas and Wireless Propagation Letters 02/2009; · 1.37 Impact Factor
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ABSTRACT: In this paper, a vertically polarized broadband antenna with an adjustable shape for specific applications in the VHF and UHF bands is proposed. This antenna is a compact monopole with a pseudo-conical shape set on a rectangular ground plane, partially made of wire netting. A part of the radiating element is made of metallic pipes which are bent to minimize the height of the shape without deteriorating the impedance matching. The bent pipes and the wire netting of the ground plane can be removed in order to dramatically reduce the size of the antenna for applications in high-frequency range. As a result, two compact structures relatively to the wavelength are obtained with a vertical size of respectively lambda<sub>LF</sub>/6.25 for the low-frequency mode (100-500 MHz) and lambda<sub>LF</sub>/7.2 for the high-frequency mode (415-915 MHz) (lambda<sub>LF</sub> is the wavelength associated to the lowest frequency of the covered bandwidth). The structures operate with good gain and radiation patterns in both E- planes and H-planes.
Microwave Conference, 2008. APMC 2008. Asia-Pacific; 01/2009
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ABSTRACT: This paper deals with radiation pattern reconfigurable antenna in millimetre wave range. An active printed antenna array is designed in 24 GHz band and feed an inhomogeneous lens (Half Maxwell Fish Eye) to obtain reconfigurable patterns and in particular sectorial and directive cases. In the first part, the authors describe a four patches multilayer active array which allows achieving radiation pattern control by associating a commutator to each element and by changing the fed patches number. In a second part, this array feed an inhomogeneous lens to shape radiation pattern.
Microwave Conference, 2008. EuMC 2008. 38th European; 12/2008
