Pub Date : 2007-03-21DOI: 10.1109/IWAT.2007.370087
Vincent Fusco
We discuss possibilities that exist when a 2-D array of wires loaded with linear lumped or with non-linear lumped elements are deployed as passive or as semi-active frequency selective surfaces. We show that such surfaces can act as an EM shutter which allows the flow of transmitted energy to be controlled. In addition it is demonstrated that the inclusion of nonlinear components allow surfaces to be made which could behave as thin planar lenses or as phase conjugating artificial media. Further, the paper discusses the anisotropic propagation properties of textured surface PCBs as means for antenna far-field radiation control
{"title":"Antenna Possibilities using 2D Planar Periodic Structures","authors":"Vincent Fusco","doi":"10.1109/IWAT.2007.370087","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370087","url":null,"abstract":"We discuss possibilities that exist when a 2-D array of wires loaded with linear lumped or with non-linear lumped elements are deployed as passive or as semi-active frequency selective surfaces. We show that such surfaces can act as an EM shutter which allows the flow of transmitted energy to be controlled. In addition it is demonstrated that the inclusion of nonlinear components allow surfaces to be made which could behave as thin planar lenses or as phase conjugating artificial media. Further, the paper discusses the anisotropic propagation properties of textured surface PCBs as means for antenna far-field radiation control","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":"133011197","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.2007.370174
Xiaojing Xu, Y. Wang
This paper addresses a fundamental issue regarding electrically small antennas. It is well known that electrically small antennas suffers the fundamental limit of high Q and can not be used for broadband radiation in conventional cases. However, it is found that by integrating high-speed switch devices on the antenna, the bandwidth limit on the radiation can be overcome. This is because the high-Q value associated with electrically small antennas no longer limits the bandwidth of radiation in such a time-varying system.
{"title":"Chu's Limit and Switched Electrically Small Antennas","authors":"Xiaojing Xu, Y. Wang","doi":"10.1109/IWAT.2007.370174","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370174","url":null,"abstract":"This paper addresses a fundamental issue regarding electrically small antennas. It is well known that electrically small antennas suffers the fundamental limit of high Q and can not be used for broadband radiation in conventional cases. However, it is found that by integrating high-speed switch devices on the antenna, the bandwidth limit on the radiation can be overcome. This is because the high-Q value associated with electrically small antennas no longer limits the bandwidth of radiation in such a time-varying system.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"33 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":"132928285","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.2007.370103
A. Diallo, C. Luxey, P. Le Thuc, R. Staraj, G. Kossiavas, M. Franzén, P. Kildal
This paper results from a short-term mission granted by the COST 284 where the antenna-design competences of the LEAT have been gathered with the measurement skills of Chalmers Institute of Technology. Three multi-antenna prototypes have been characterized in the Bluetest reverberation chamber in terms of total efficiency and diversity gain. Particularly the performances of an initial four-antenna system with poor isolation have been evaluated with and without the presence of a phantom head and then we characterized in the same manner two prototypes with highly decoupled antennas. The paper especially focused on demonstrating that the neutralization technique is still giving improvements in the presence of the user's head.
{"title":"Evaluation of the performances of several four-antenna systems in a reverberation chamber","authors":"A. Diallo, C. Luxey, P. Le Thuc, R. Staraj, G. Kossiavas, M. Franzén, P. Kildal","doi":"10.1109/IWAT.2007.370103","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370103","url":null,"abstract":"This paper results from a short-term mission granted by the COST 284 where the antenna-design competences of the LEAT have been gathered with the measurement skills of Chalmers Institute of Technology. Three multi-antenna prototypes have been characterized in the Bluetest reverberation chamber in terms of total efficiency and diversity gain. Particularly the performances of an initial four-antenna system with poor isolation have been evaluated with and without the presence of a phantom head and then we characterized in the same manner two prototypes with highly decoupled antennas. The paper especially focused on demonstrating that the neutralization technique is still giving improvements in the presence of the user's head.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"29 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":"130518645","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.2007.370140
M. Jalali, A. Abdipour, A. Tavakoli, G. Moradi
This paper describes the implementation of an active integrated spiral antenna for UWB (ultra-wideband) applications. By integrating a low-noise amplifier with antenna, the voltage standing wave ratio (VSWR) can be kept low for a large bandwidth and this antenna indicate a 13 dB improvement in gain compared with one using a passive antenna with the same design, resulting in an improved spiral antenna performance for UWB. For the designed circuit in the UWB frequency range (3.1-10.6 GHz), the gain of the LNA is better than 13 dB, its noise figure is less than 3 dB, S11 and S22 are less than -13 dB, respectively
本文介绍了一种用于超宽带应用的有源集成螺旋天线的实现。通过将低噪声放大器与天线集成，可以在大带宽下保持低电压驻波比(VSWR)，与采用相同设计的无源天线相比，该天线的增益提高了13 dB，从而提高了超宽带螺旋天线的性能。设计的电路在UWB频率范围(3.1-10.6 GHz)内，LNA的增益优于13 dB，噪声系数小于3 dB, S11和S22分别小于-13 dB
{"title":"Performance Amelioration of an Active Integrated Spiral Antenna System for UWB Applications","authors":"M. Jalali, A. Abdipour, A. Tavakoli, G. Moradi","doi":"10.1109/IWAT.2007.370140","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370140","url":null,"abstract":"This paper describes the implementation of an active integrated spiral antenna for UWB (ultra-wideband) applications. By integrating a low-noise amplifier with antenna, the voltage standing wave ratio (VSWR) can be kept low for a large bandwidth and this antenna indicate a 13 dB improvement in gain compared with one using a passive antenna with the same design, resulting in an improved spiral antenna performance for UWB. For the designed circuit in the UWB frequency range (3.1-10.6 GHz), the gain of the LNA is better than 13 dB, its noise figure is less than 3 dB, S11 and S22 are less than -13 dB, respectively","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"292 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":"116573411","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.2007.370089
I. Nefedov, A. Tarot, K. Mahdjoubi
We discuss antenna miniaturization using new metamaterials, combining advantages of artificial dielectric and natural magnetic materials. It is known that the reduction of an antenna size using dielectric substrate causes the decrease of the antenna bandwidth. At the same time, the inclusion of magnetic materials into substrate allows to increase the bandwidth. It stimulates attempts to use artificial magnetics inserted into substrates of patch antennas. However, such a way did not bring considerable successes due to some reasons, mainly due to difficulties to achieve simultaneously a noticeable real part and small imaginary part of permeability in a sufficient frequency range. In this paper we propose to use as a substrate a magnetized ferrite filled with wire media whose role is to reduce the effective permittivity of the substrate. Our estimations, based on the transmission line theory, show that the radiation quality factor can be strongly minimized using the proposed substrate
{"title":"Wire Media - Ferrite Substrate for Patch Antenna Miniaturization","authors":"I. Nefedov, A. Tarot, K. Mahdjoubi","doi":"10.1109/IWAT.2007.370089","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370089","url":null,"abstract":"We discuss antenna miniaturization using new metamaterials, combining advantages of artificial dielectric and natural magnetic materials. It is known that the reduction of an antenna size using dielectric substrate causes the decrease of the antenna bandwidth. At the same time, the inclusion of magnetic materials into substrate allows to increase the bandwidth. It stimulates attempts to use artificial magnetics inserted into substrates of patch antennas. However, such a way did not bring considerable successes due to some reasons, mainly due to difficulties to achieve simultaneously a noticeable real part and small imaginary part of permeability in a sufficient frequency range. In this paper we propose to use as a substrate a magnetized ferrite filled with wire media whose role is to reduce the effective permittivity of the substrate. Our estimations, based on the transmission line theory, show that the radiation quality factor can be strongly minimized using the proposed substrate","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"66 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":"121927805","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.2007.370183
Di Li, Yi Huang
The photoconductive antenna is the most widely used device to generate and detect the terahertz (THz) wave but it has a limitation that the generated power is very low. There have been some investigations into how to increase the radiated THz power and it was found that to excite at a point is a practical method to improve the efficiency. In this paper, a theory is developed to support this idea. The analysis shows the reason why excitation at a point can generate higher THz power than the whole gap excitation of photoconductive antenna.
{"title":"A Theory of How to Improve the Radiation of the Photoconductive Antenna","authors":"Di Li, Yi Huang","doi":"10.1109/IWAT.2007.370183","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370183","url":null,"abstract":"The photoconductive antenna is the most widely used device to generate and detect the terahertz (THz) wave but it has a limitation that the generated power is very low. There have been some investigations into how to increase the radiated THz power and it was found that to excite at a point is a practical method to improve the efficiency. In this paper, a theory is developed to support this idea. The analysis shows the reason why excitation at a point can generate higher THz power than the whole gap excitation of photoconductive antenna.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"207 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":"124662563","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.2007.370139
X. Bao, Max J. Ammann
The development of the high data rate wireless communication systems, has placed significant demands on antenna designers, in particular, the requirement for smaller elements with broader bandwidths. In this paper, a novel UWB antenna with notch-band frequency is studied. Effects of the various parameters for antenna performances are also discussed. An optimized compact UWB antenna with notch-frequency function is fabricated and experimentally examined. The measured results show the proposed UWB antenna can achieve a return loss greater than 10 db over an ultrawide bandwidth, of 9.8 GHz, from 2.97 GHz to 12.77 GHz with a tunable notch-frequency band of 5.15 GHz to 5.825 GHz
高数据速率无线通信系统的发展对天线设计人员提出了很高的要求，特别是对更小的元件和更宽的带宽的要求。本文研究了一种新型的带陷波带的超宽带天线。讨论了各参数对天线性能的影响。制作了一种具有陷波函数的优化紧凑型超宽带天线，并进行了实验验证。测量结果表明，该天线在2.97 ~ 12.77 GHz的超宽带带宽(9.8 GHz)和5.15 ~ 5.825 GHz的可调缺口频带范围内，回波损耗大于10 db
{"title":"Printed Band-Rejection UWB Antenna with H-shaped Slot","authors":"X. Bao, Max J. Ammann","doi":"10.1109/IWAT.2007.370139","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370139","url":null,"abstract":"The development of the high data rate wireless communication systems, has placed significant demands on antenna designers, in particular, the requirement for smaller elements with broader bandwidths. In this paper, a novel UWB antenna with notch-band frequency is studied. Effects of the various parameters for antenna performances are also discussed. An optimized compact UWB antenna with notch-frequency function is fabricated and experimentally examined. The measured results show the proposed UWB antenna can achieve a return loss greater than 10 db over an ultrawide bandwidth, of 9.8 GHz, from 2.97 GHz to 12.77 GHz with a tunable notch-frequency band of 5.15 GHz to 5.825 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":"129889883","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.2007.370119
L. Yousefi, O. Ramahi
In this paper, new artificial magnetic materials based on fractal Hilbert curves are proposed, modeled and numerically analyzed. It is shown that using fractal structures as inclusion in the design of artificial magnetic materials allows miniaturization of the unit cell size, thus enabling design of miniaturized devices such as antennas. Furthermore it is proven analytically and numerically that these new materials are less dispersive in comparison to conventional split rings
{"title":"New Artificial Magnetic Materials Based on Fractal Hilbert Curves","authors":"L. Yousefi, O. Ramahi","doi":"10.1109/IWAT.2007.370119","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370119","url":null,"abstract":"In this paper, new artificial magnetic materials based on fractal Hilbert curves are proposed, modeled and numerically analyzed. It is shown that using fractal structures as inclusion in the design of artificial magnetic materials allows miniaturization of the unit cell size, thus enabling design of miniaturized devices such as antennas. Furthermore it is proven analytically and numerically that these new materials are less dispersive in comparison to conventional split rings","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":"129731689","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.2007.370131
Huagang Sun, Wen Xun Zhang
Transmit-array (TA) has advantages such as low profile, easy fabrication, flexible element structure, and multi-function etc. It receives spherical wave and adjust its phases to re-radiate forwards. TA avoids the effect of feed blockage existing in a reflect-array, can realize arbitrarily linear polarization transform well. In this paper two kinds of broadband element of TA with polarization transform are proposed, their properties of phase compensation, polarization transform and transmission efficiency are analyzed and compared
{"title":"Design of Broadband Element of Transmit-array with Polarization Transform","authors":"Huagang Sun, Wen Xun Zhang","doi":"10.1109/IWAT.2007.370131","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370131","url":null,"abstract":"Transmit-array (TA) has advantages such as low profile, easy fabrication, flexible element structure, and multi-function etc. It receives spherical wave and adjust its phases to re-radiate forwards. TA avoids the effect of feed blockage existing in a reflect-array, can realize arbitrarily linear polarization transform well. In this paper two kinds of broadband element of TA with polarization transform are proposed, their properties of phase compensation, polarization transform and transmission efficiency are analyzed and compared","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"11 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":"127600872","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.2007.370155
A. Karlsson
The fundamental limits of the gain, efficiency and Q-value of an antenna put severe restrictions on small antennas. In this paper it is discussed how one can avoid low efficiency and high Q-values in small antennas by examining the far-field pattern of the antenna. The analysis is based on the expansion of the electromagnetic fields in terms of vector spherical harmonics.
{"title":"Efficiency, gain and Q of antennas","authors":"A. Karlsson","doi":"10.1109/IWAT.2007.370155","DOIUrl":"https://doi.org/10.1109/IWAT.2007.370155","url":null,"abstract":"The fundamental limits of the gain, efficiency and Q-value of an antenna put severe restrictions on small antennas. In this paper it is discussed how one can avoid low efficiency and high Q-values in small antennas by examining the far-field pattern of the antenna. The analysis is based on the expansion of the electromagnetic fields in terms of vector spherical harmonics.","PeriodicalId":446281,"journal":{"name":"2007 International workshop on Antenna Technology: Small and Smart Antennas Metamaterials and Applications","volume":"129 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":"115641717","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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