2007 Loughborough Antennas and Propagation Conference最新文献

{"title":"Cost-Variant Sage: Field Trails and Results","authors":"N. Tyler, B. Allen, A. Aghvami","doi":"10.1109/LAPC.2007.367439","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367439","url":null,"abstract":"By extending the Space-Alternating Generalised Expectation-Maximisation (SAGE) parameter estimation algorithm to include a novel cost variant process, the robustness of Direction of Arrival (DoA) estimation from the SAGE algorithm is shown here to improve. A novel extension to the standard SAGE algorithm that enhances the parameter estimation process is first introduced. Field trials that have been conducted using an adaptive antenna to verify the performance of this algorithm are presented. Results show the extended SAGE algorithm improves DoA performance compared to standard SAGE by 5deg when operating in an urban environment.","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127388642","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}

{"title":"Three-Dimensional Electromagnetic Approach to the Modeling of Time Reversal Technique for Communication","authors":"A. Khaleghi, G. El Zein","doi":"10.1109/LAPC.2007.367469","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367469","url":null,"abstract":"In this paper, we introduce a three-dimensional electromagnetic approach to the modeling of time reversal (TR) technique in communication. The proposed method uses time-domain transmission line matrix (TD-TLM) method for the computation of the channel response in a rich scattering environment. The time-reversed version of the computed channel response is used as the source signal of the transmitting antenna. The electromagnetic solution is repeated and the characteristic of the TR channel is assessed.","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121579994","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}

{"title":"A Novel Ultra Wideband Antenna for UWB Applications","authors":"A. Mehdipour, H. Aliakbarian, M. Kamarei","doi":"10.1109/LAPC.2007.367467","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367467","url":null,"abstract":"In this paper, a new ultra-wideband (UWB) antenna for UWB applications is proposed. The presented antenna is designed to operate from 1.8 to 12 GHz. Regarding high bandwidth, antenna size and commercial aspects in design procedure, the manufacturability of antenna is considered also. Details of the antenna design and related results are presented and discussed.","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122773484","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}

{"title":"Challenges in Antenna Designs and Some Novel Techniques for Meeting Them","authors":"R. Mittra","doi":"10.1109/LAPC.2007.367420","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367420","url":null,"abstract":"In this paper we identify some challenges in antenna designs-both small and large types-that we have recently encountered in the process of designing antennas for personal communication, GPS, UWB, Millimeter waves, BANs (body area networks), sensors, RFID, and other similar applications. The primary challenges in designing small antennas arise from the specifications that are often very demanding in terms of performance expectations, e.g., gain, bandwidth, pattern characteristics (including polarization), decreased sensitivity to the environment, etc., even as the above specs concurrently place severe restrictions on the size of the available real estate in which the antenna is to be placed. We should mention that even though the antenna itself may be small, the degrees of freedom (DOFs) associated with the problem description can still be large, especially when dealing with antenna/metamaterial composites, which often pose a considerable challenge when one attempts to simulate them. Needless to say that the topic of metamaterial has attracted considerable attention in recent years, as evidenced by the number of researcher contributing to the subject, who have been very prolific indeed. It would be presumptive to attempt to fully cover and renew these developments in this presentation-given the time limitation-because it would be impossible to do justice to the diverse away of facets that have all been grouped under the general umbrella of \"Metamaterials.\" In view of this, we narrow our focus down to the topic of \"Performance Enhancement of Small Antennas using Metamaterials,\" because such enhancements are certain to have a very large impact on communication antenna design, which, we believe to be a centerpiece topic of this conference. The first impression that comes to one's mind when one scans through and takes a cursory look at the vast array of publications that discuss antenna-material composites is that the metamaterials provide the proverbial \"Midas touch,\" a veritable magic bullet for curing everything that ails the small antennas. If we were to compile a wish-list for the desired features of small antennas, we would most probably include: wide bandwidth in terms of both impedance match (return loss) and radiation pattern, high directivity, and conformal nature-to name just a few of the desirable attributes of the antennas that we might be designing for communication, RFID, GPS, LAN or BAN applications. Some of the small antenna/metamaterial composite type of configurations to be discussed in the presentation are shown in Figs. 1 through 5. For large antennas, the design goals are often very different, and the emphasis here may be to realize ultra-low sidelobes, reduce EMI, achieve superior EMC characteristics, etc., just to name a few. Here, the challenge often is how to model these large structures in an accurate and efficient manner so that their performance can be predicted reliably and confidently, before the antenna is actually fab","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131733564","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}

{"title":"E-Plane Cut UWB Monopole","authors":"B. Sanz-Izquierdo, J. Batchelor","doi":"10.1109/LAPC.2007.367451","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367451","url":null,"abstract":"This paper presents a novel compact, dual layer UWB monopole antenna design. The low profile dimensions of the antenna are achieved by removing a symmetrical section of a previously developed dual layer design. Similarly to the original antenna, the antenna uses two substrate layers and a 50 ohms part-shielded strip-line with an array of metal vias making the conducting walls. A half disc monopole forms the radiating element and the novel dual layer part-shielded strip line feed allows for integration in multilayer technologies. The ultra-wideband monopole characteristics of the antenna are confirmed experimentally.","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115058175","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}

{"title":"Compact Fabry-Perot Cavities in x-band with PEC and PMC Boundary Conditions","authors":"O. Roncière, R. Sauleau, K. Mahdjoubi, H. Legay","doi":"10.1109/LAPC.2007.367489","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367489","url":null,"abstract":"Resonator antennas based on Fabry-Perot (FP) cavities are low-profile directive antennas widely studied for moderate or high-gain applications. In contrast to previous studies, we investigate here their capabilities when employed as primary sources of Focal-Array Fed Reflector antennas (FAFR) for space applications in X-band. In addition to standard specifications in terms of bandwidth, return loss and radiation efficiency, one of the main requirements not addressed in prior works consists of the optimization of their aperture efficiency. To this end, we first investigate numerically the radiation performance of pure metallic (PEC) compact FP antennas whose size is in the order of a few wavelengths. Their key features are discussed and compared with the well-known characteristics of electrically large FP antennas. In particular, it is shown that there exists an optimum value for the grid reflectivity in order to maximize the antenna aperture efficiency. Then, a new TEM-mode FP antenna with PMC walls (closely-coupled printed dipoles on a grounded substrate) in H-plane is proposed. This configuration enables one to enhance significantly the aperture efficiency of the antenna as well as to produce an axis-symmetric beam, which is not possible with compact FP cavities with PEC walls.","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130842401","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}

{"title":"Planar Roof Mounted Automotive Antenna","authors":"L. Low, R. Langley, R. Breden, P. Callaghan","doi":"10.1109/LAPC.2007.367443","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367443","url":null,"abstract":"A planar antenna installed under an aperture in the roof of a sports utility vehicle is presented. It provides an alternative location for antenna placement on a vehicle. The antenna measures 88.2 cm times 18.5 cm and has seven feeds and is capable of covering simultaneous operation of the following communications systems; FM, AM, TV, TMC and DAB audio reception. A comparison of measurements and simulations of the proposed antenna system was carried out at the FM broadcast band at 100 MHz.","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130536785","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}

{"title":"Modified Designs for UWB Planar Monopole Antennas","authors":"I. Makris, D. Manteuffel, R. Seager, J. Vardaxoglou","doi":"10.1109/LAPC.2007.367476","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367476","url":null,"abstract":"This paper reports a theoretical study of a planar monopole antenna for use in the 3.1 GHz-10.6 GHz UWB band for later integration into consumer electronic products. Therefore the emphasis of the research is related to minimizing the size of the monopole while maintaining the matching in the desired frequency range. Simulations, using the Empire Software Suite, show that the impedance matched bandwidth (RL>10 dB) can be significantly increased by bevelling the bottom edge of the monopole and also the impedance match at the lower end of the band can be improved by judicious placement of a shorting pin. The use of a 1 mm wide shorting pin yields a structure that resembles a PIFA antenna. It is possible to treat the monopole antenna as a modified PIFA and apply transmission line theory to predicting the resonant frequencies and the return loss. A combination of shorting pin with bevel shows significant promise in the size reduction of the UWB antennas. The key point is the careful position of the shorting pin (with the bevel) on the monopole that to give a very good match through out the UWB band. This paper reports an investigation of the effect of the antenna dimensions (height, bevel angle and position of shorting pin) on its broad band response. The results of this study show that it is possible to reduce the size of the antenna elements significantly below lambdamax/4, when additional shorting pins are used on the antenna. The distributed shorting pins can be understood to work as a matching network for the antenna.","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126822722","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}

{"title":"Dispersion Characteristics of a Perturbed EBG Waveguide with Periodic Resonant Loads","authors":"G. Goussetis","doi":"10.1109/LAPC.2007.367472","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367472","url":null,"abstract":"By altering the gap of every other ridge waveguide load it is possible to produce a perturbed Electromagnetic Band Gap E-plane waveguide. By virtue of the perturbation the irreducible Brillouin zone is halved and a new Bragg reflection band gap emerges. Moreover, due to the resonance of the perturbed load an additional transmission zero emerges. These effects are here identified by studying the dispersion relation of equivalent circuits. Full wave results are presented for validation. This topology increases the flexibility for introducing multiple transmission zeros in the band gap.","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126874576","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}

{"title":"Antenna over Ground Plane for Wideband Communications","authors":"P. Plaivech, R. Langley","doi":"10.1109/LAPC.2007.367465","DOIUrl":"https://doi.org/10.1109/LAPC.2007.367465","url":null,"abstract":"The performance of an antenna designed to work on a PCMCIA card with a wide frequency bandwidth is presented. The antenna uses two low profile elements that are fed via a single microstrip line. The overall height of the antenna was 8.5 mm and the base was 86 mm x 54 mm. A bandwidth of 2:1 was measured and the resulting radiation patterns are satisfactory across the band from 5 GHz to 10 GHz.","PeriodicalId":349412,"journal":{"name":"2007 Loughborough Antennas and Propagation Conference","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127132817","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}