Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370158
M. Kamarudin, P. Hall, F. Colombel, M. Himdi
A switched beam disk-loaded parasitic monopole antenna array with coplanar waveguide (CPW) feeding systems with integrated PIN diode switches is described. The measured gain of the antenna in the direction of the open-circuited parasite element is in the range of 5.1 dBi to 5.6 dBi. It was confirmed that by changing the control current to the switches, the main beam direction of the antenna can be switched in the azimuthal plane. The reflection coefficient for all four configurations is matched at 2.45 GHz.
{"title":"CPW-Fed Disc-loaded Monopole Array Antenna with Integrated PIN Diode Switches","authors":"M. Kamarudin, P. Hall, F. Colombel, M. Himdi","doi":"10.1109/IWAT.2007.370158","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370158","url":null,"abstract":"A switched beam disk-loaded parasitic monopole antenna array with coplanar waveguide (CPW) feeding systems with integrated PIN diode switches is described. The measured gain of the antenna in the direction of the open-circuited parasite element is in the range of 5.1 dBi to 5.6 dBi. It was confirmed that by changing the control current to the switches, the main beam direction of the antenna can be switched in the azimuthal plane. The reflection coefficient for all four configurations is matched at 2.45 GHz.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121223101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370125
N. Guan, H. Furuya, K. Himeno, K. Goto, K. Ito
As mobile wireless communications have progressed dramatically in recent years, many mobile terminals are becoming smaller and smaller and miniaturization of the antennas employed in mobile devices is required accordingly. In this paper, a monopole antenna that consists of one-half of a bow-tie dipole antenna, made of optically transparent conductive thin film and mounted above a ground plane, is investigated. The antenna is designed to work at 2.4 GHz and the radiation element of the antenna is made of several transparent conductive films with different sheet resistivities. It is found that the gain lowering of the antenna varies from 4.4 dB to 0.2 dB at 2.4 GHz, and the efficiency of the antenna increases from 46% to 93% at the same frequency, as the sheet resistivity of the film decreases from 19.8 Omega/sq to 1.3 Omega/sq, respectively. The antenna is analyzed by a wire-grid model based on the moment method. The resistance of the film is taken into account by parallelly loading a resistance on every discretized element. It is demonstrated after that the analyzed results are in good agreement with the experimental ones
{"title":"A Monopole Antenna Made of a Transparent Conductive Film","authors":"N. Guan, H. Furuya, K. Himeno, K. Goto, K. Ito","doi":"10.1109/IWAT.2007.370125","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370125","url":null,"abstract":"As mobile wireless communications have progressed dramatically in recent years, many mobile terminals are becoming smaller and smaller and miniaturization of the antennas employed in mobile devices is required accordingly. In this paper, a monopole antenna that consists of one-half of a bow-tie dipole antenna, made of optically transparent conductive thin film and mounted above a ground plane, is investigated. The antenna is designed to work at 2.4 GHz and the radiation element of the antenna is made of several transparent conductive films with different sheet resistivities. It is found that the gain lowering of the antenna varies from 4.4 dB to 0.2 dB at 2.4 GHz, and the efficiency of the antenna increases from 46% to 93% at the same frequency, as the sheet resistivity of the film decreases from 19.8 Omega/sq to 1.3 Omega/sq, respectively. The antenna is analyzed by a wire-grid model based on the moment method. The resistance of the film is taken into account by parallelly loading a resistance on every discretized element. It is demonstrated after that the analyzed results are in good agreement with the experimental ones","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124944366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370088
C. Qiu, S. Zouhdi, Lewei Li
Negative refraction in microwave region have been achieved by requiring two appropriate resonances in the same frequency range. To date, most of the experimental results concerning NIM are in the microwave frequency range, with only a few preliminary results of NIMs available at sub-mm wave and infrared frequencies. The impact of negative index media would be much larger if one can realize negative refraction at optical frequencies. An alternative approach to achieve backward waves and negative refraction at optical frequencies is proposed via magnetoelectric couplings. The gyrotropy effects of those couplings are also examined and potential applications are discussed
{"title":"Functional Materials with Magnetoelectric Couplings and Gyrotropy","authors":"C. Qiu, S. Zouhdi, Lewei Li","doi":"10.1109/IWAT.2007.370088","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370088","url":null,"abstract":"Negative refraction in microwave region have been achieved by requiring two appropriate resonances in the same frequency range. To date, most of the experimental results concerning NIM are in the microwave frequency range, with only a few preliminary results of NIMs available at sub-mm wave and infrared frequencies. The impact of negative index media would be much larger if one can realize negative refraction at optical frequencies. An alternative approach to achieve backward waves and negative refraction at optical frequencies is proposed via magnetoelectric couplings. The gyrotropy effects of those couplings are also examined and potential applications are discussed","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128508529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370071
A. Erentok, R. Ziolkowski
Easy to build, efficient and electrically-small antenna designs are presented which are based on a two-dimensional (2D) metamaterial-inspired structure that incorporates a lumped element capacitor in its design and that is driven by an electrically-small rectangular semi-loop antenna fed by a coaxial cable through a finite PEC ground plane. Measured reflection coefficients showed a very good agreement with the simulated data, where the measured resonant frequency is only 0.7% below the numerically predicted value. The proposed lumped capacitor based 2D antenna systems are scalable to a desired frequency and predicted radiation characteristics of the antenna systems at 100 MHz, 450 MHz and 1575 MHz are reported.
{"title":"Lumped Element Capacitor Based Two-Dimensional Efficient Metamaterial-inspired Electrically-Small Antenna","authors":"A. Erentok, R. Ziolkowski","doi":"10.1109/IWAT.2007.370071","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370071","url":null,"abstract":"Easy to build, efficient and electrically-small antenna designs are presented which are based on a two-dimensional (2D) metamaterial-inspired structure that incorporates a lumped element capacitor in its design and that is driven by an electrically-small rectangular semi-loop antenna fed by a coaxial cable through a finite PEC ground plane. Measured reflection coefficients showed a very good agreement with the simulated data, where the measured resonant frequency is only 0.7% below the numerically predicted value. The proposed lumped capacitor based 2D antenna systems are scalable to a desired frequency and predicted radiation characteristics of the antenna systems at 100 MHz, 450 MHz and 1575 MHz are reported.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125750731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370165
Lu Guo, M. Rehman, Jianxin Liang, Xiao-dong Chen, C. Parini
This paper presents an investigation of cross ring/disc antenna for UWB applications. A coaxial cable fed cross the ring antenna with satisfactory -10 dB return loss bandwidth is firstly designed. In order to minimize the radiation pattern distortion at 9 GHz, an extended ground plane is then introduced. A comparison of performance of four different kinds of cross ring/disc antennas is also illustrated.
{"title":"A Study of Cross Ring Antenna for UWB Applications","authors":"Lu Guo, M. Rehman, Jianxin Liang, Xiao-dong Chen, C. Parini","doi":"10.1109/IWAT.2007.370165","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370165","url":null,"abstract":"This paper presents an investigation of cross ring/disc antenna for UWB applications. A coaxial cable fed cross the ring antenna with satisfactory -10 dB return loss bandwidth is firstly designed. In order to minimize the radiation pattern distortion at 9 GHz, an extended ground plane is then introduced. A comparison of performance of four different kinds of cross ring/disc antennas is also illustrated.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125279864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370112
H. Wong, K. Luk
A new wideband antenna composed of a folded dipole and a vertically folded shorted patch is presented in this paper. Employing a folding technique, the height of the antenna could be reduced from 0.25lambda to 0.15lambda. The antenna is excited by a Gamma-shaped strip, consisting of an air microstrip line and an L-shaped coupled strip line. With the presence of the coupled line, the antenna yields a wide impedance bandwidth of 48.4% (SWRles2) from 2.249 to 3.687 GHz. Moreover, through the combination of two radiating elements (i.e. the planar dipole and the shorted patch), the antenna finds a stable broadside radiation pattern across the entire operating bandwidth with low cross-polarization and low back radiation. The proposed antenna has a maximum antenna gain of approximately 6 dBi.
{"title":"Wideband antenna with a folded dipole and a folded shorted patch","authors":"H. Wong, K. Luk","doi":"10.1109/IWAT.2007.370112","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370112","url":null,"abstract":"A new wideband antenna composed of a folded dipole and a vertically folded shorted patch is presented in this paper. Employing a folding technique, the height of the antenna could be reduced from 0.25lambda to 0.15lambda. The antenna is excited by a Gamma-shaped strip, consisting of an air microstrip line and an L-shaped coupled strip line. With the presence of the coupled line, the antenna yields a wide impedance bandwidth of 48.4% (SWRles2) from 2.249 to 3.687 GHz. Moreover, through the combination of two radiating elements (i.e. the planar dipole and the shorted patch), the antenna finds a stable broadside radiation pattern across the entire operating bandwidth with low cross-polarization and low back radiation. The proposed antenna has a maximum antenna gain of approximately 6 dBi.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116753826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370070
Jørgen Bach Andersen, B. K. Lau
Recent work on compact multiple antennas in a random environment is reviewed, including extensions of the energy density antenna and the MIMO cube. The performance of handsets with multiple antennas is dependent on many factors due to the close proximity of the antennas. The distribution of scatterers in the environment has an impact on the distributed directivity of the antennas, the powers absorbed in the loads, and the correlation between the open-circuit signals. Matching the antennas is non-trivial, since the matching changes the output correlations and the efficiency. The antennas may be matched for maximum MIMO capacity for a given environment. Basic bandwidth limitations are also discussed.
{"title":"Compact Multiple Antennas in a Random World","authors":"Jørgen Bach Andersen, B. K. Lau","doi":"10.1109/IWAT.2007.370070","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370070","url":null,"abstract":"Recent work on compact multiple antennas in a random environment is reviewed, including extensions of the energy density antenna and the MIMO cube. The performance of handsets with multiple antennas is dependent on many factors due to the close proximity of the antennas. The distribution of scatterers in the environment has an impact on the distributed directivity of the antennas, the powers absorbed in the loads, and the correlation between the open-circuit signals. Matching the antennas is non-trivial, since the matching changes the output correlations and the efficiency. The antennas may be matched for maximum MIMO capacity for a given environment. Basic bandwidth limitations are also discussed.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130196375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370144
S. T. Low, Zhipeng Wu
Microstrip-feed enables possible integration of dielectric resonator antenna (DRA) with other microwave circuits in a planar arrangement. In the past critical coupling of microstrip-coupled DRA is found by experimentally adjusting the position of the DRA with respect to the microstrip line. The objective of the study reported in this paper is to provide an insight of how a microstrip line could efficiently couple electromagnetic energy to a rectangular dielectric resonator antenna (RDRA) on different PCB substrates. Antenna parameters under investigation include the resonant frequency, return loss, impedance bandwidth and the co- to cross-polarisation levels. The PCB substrates investigated include RT/duroid 5880 and FR4 of different thicknesses. The results of this study are presented.
{"title":"Microstrip-Coupled Rectangular Dielectric Resonator Antennas on Different Substrates","authors":"S. T. Low, Zhipeng Wu","doi":"10.1109/IWAT.2007.370144","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370144","url":null,"abstract":"Microstrip-feed enables possible integration of dielectric resonator antenna (DRA) with other microwave circuits in a planar arrangement. In the past critical coupling of microstrip-coupled DRA is found by experimentally adjusting the position of the DRA with respect to the microstrip line. The objective of the study reported in this paper is to provide an insight of how a microstrip line could efficiently couple electromagnetic energy to a rectangular dielectric resonator antenna (RDRA) on different PCB substrates. Antenna parameters under investigation include the resonant frequency, return loss, impedance bandwidth and the co- to cross-polarisation levels. The PCB substrates investigated include RT/duroid 5880 and FR4 of different thicknesses. The results of this study are presented.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131481749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370180
Yan Zhao, P. Belov, Y. Hao
This paper presents the modelling of wire medium using a finite-difference time-domain (FDTD) method. The flat subwavelength lenses formed by the wire medium (lattices of parallel metallic wires) have been modelled in FDTD through the effect medium approach. The auxiliary differential equation (ADE) method has been applied in FDTD model in order to take into account both the frequency dispersion effect and the spatial dispersion effect which was found recently. The developed formulas have been implemented in a two-dimensional (2-D) FDTD model and validated by comparing transmission coefficient calculated from analytical solutions. The simulation results demonstrate the subwavelength imaging capability of the wire medium lenses.
{"title":"Spatially Dispersive Finite-Difference Time-Domain Modelling of the Wire Medium for Subwavelength Imaging","authors":"Yan Zhao, P. Belov, Y. Hao","doi":"10.1109/IWAT.2007.370180","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370180","url":null,"abstract":"This paper presents the modelling of wire medium using a finite-difference time-domain (FDTD) method. The flat subwavelength lenses formed by the wire medium (lattices of parallel metallic wires) have been modelled in FDTD through the effect medium approach. The auxiliary differential equation (ADE) method has been applied in FDTD model in order to take into account both the frequency dispersion effect and the spatial dispersion effect which was found recently. The developed formulas have been implemented in a two-dimensional (2-D) FDTD model and validated by comparing transmission coefficient calculated from analytical solutions. The simulation results demonstrate the subwavelength imaging capability of the wire medium lenses.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114103501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370166
L. Yousefi, B. Mohajer-Iravani, O. Ramahi
In this paper, a novel application for magneto-dielectric materials is introduced. Using magneto-dielectric materials, a compact wide band electromagnetic bandgap (EBG) structure is designed. The numerical results show that this EBG has an in-phase reflection bandwidth of 70% which is several times greater than a conventional EBG resonating at the same frequency while its cell size is smaller. Using this EBG as the ground plane, a low profile unidirectional spiral antenna is designed to operate over the 8 to 18 GHz. The VSWR and gain of the designed low profile antenna is shown to be comparable to the PEC backed spiral antenna (backing at lambda/4), while achieving a 72% reduction in profile.
{"title":"Low Profile Wide Band Antennas using Electromagnetic Bandgap Structures with Magneto-Dielectric Materials","authors":"L. Yousefi, B. Mohajer-Iravani, O. Ramahi","doi":"10.1109/IWAT.2007.370166","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370166","url":null,"abstract":"In this paper, a novel application for magneto-dielectric materials is introduced. Using magneto-dielectric materials, a compact wide band electromagnetic bandgap (EBG) structure is designed. The numerical results show that this EBG has an in-phase reflection bandwidth of 70% which is several times greater than a conventional EBG resonating at the same frequency while its cell size is smaller. Using this EBG as the ground plane, a low profile unidirectional spiral antenna is designed to operate over the 8 to 18 GHz. The VSWR and gain of the designed low profile antenna is shown to be comparable to the PEC backed spiral antenna (backing at lambda/4), while achieving a 72% reduction in profile.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125089682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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