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2001 Eleventh International Conference on Antennas and Propagation, (IEE Conf. Publ. No. 480)

17-20 April 2001

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  • Hybrid method for time-domain analysis of wire antennas embedded in a scattering dielectric medium

    Publication Year: 2001, Page(s):861 - 865 vol.2
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (309 KB)

    A hybrid time domain method for the analysis of embedded wire antennas is presented. The radiation from wire antennas placed within a heterogeneous dielectric medium is strongly dependent on near-field coupling effects and backscatter from material discontinuities. A time-domain MoM solution for the embedded wire antenna is combined with an FDTD model of the surrounding dielectric structure. The i... View full abstract»

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  • Antenna design and optimization with CLASP

    Publication Year: 2001, Page(s):470 - 474 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (528 KB)

    The CLASP suite of computer programs is some of the most advanced software in the UK for electromagnetic analysis using the method of moments in the frequency domain. This paper describes a variety of practical design calculations of antenna directivity using the software View full abstract»

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  • TEC specification over Europe: a procedure

    Publication Year: 2001, Page(s):802 - 805 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (300 KB)

    Ionospheric specification and forecasting are important parts of space weather research that seek to specify and predict conditions in the ionosphere and to determine their effects on radio wave propagation. This formidable task can be partly solved by continuous monitoring of the ionospheric state in conjunction with empirical relations. The author describes a procedure for ionospheric vertical t... View full abstract»

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  • Vector evaluated GA-ICT for optimum design of arbitrarily arranged wire grid model antenna

    Publication Year: 2001, Page(s):465 - 469 vol.2
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (284 KB)

    GA-ICT is a new method that combines a genetic algorithm (GA) and improved circuit theory (ICT) to determine the optimum antenna design without having to provide an initial basic structure. It is considered as a kind of multi-objective optimization to satisfy all design conditions such as directivity, beam width, and side lobe level. In this case, it may become difficult to obtain all design requi... View full abstract»

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  • The computer simulation of the HF-channel

    Publication Year: 2001, Page(s):797 - 801 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (376 KB)

    Communication facilities, exploiting the entire HF channel band or the greater part of it, have been widely introduced today. At the same time there are no models of the channel permitting realisation of the testing and trials, and, finally, investigations into the operation of wide-band communication systems under conditions close to actual. We give an account of the build-up and operational expe... View full abstract»

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  • Prediction of far-field bistatic scattering cross section using spherical, cylindrical and planar scanned near-field data

    Publication Year: 2001, Page(s):599 - 602 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (204 KB)

    The far-field radar cross section (RCS) measurement of a large scatterer is generally difficult due to the limitation of available measurement range. One way to avoid this difficulty is to adopt a scale model by compact range measurement. However, there are some problems in this measurement: it is labour intensive and expensive to construct the scale model, and the frequency characteristics of the... View full abstract»

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  • Analysis of antenna interactions using the INSTANT software

    Publication Year: 2001, Page(s):736 - 740 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (780 KB)

    INSTANT (short for INSTalled ANTenna performance) is a ray-tracing software suite that accurately predicts antenna behaviour, including antenna-antenna interactions, in the presence of conducting bodies, such as aircraft, ships and land vehicles. Special features of INSTANT are its direct use of a NURBS (non-uniform rational B-spline) representation to model surfaces and its employment of computer... View full abstract»

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  • Multi-band annular slot antenna for WLAN applications

    Publication Year: 2001, Page(s):529 - 532 vol.2
    Cited by:  Papers (5)  |  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (236 KB)

    A novel multi-band antenna is presented. The structure principle is based on the annular slot antenna. It consists of associating on the same microstrip fed line several of these elementary radiating elements. Each annular slot is then designed to work at one of the desired frequencies. The concept is validated on a dual-band (2.4 GHz and 5.2 GHz) topology, which has been defined to assure a good ... View full abstract»

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  • Optimisation of a dual-band printed antenna for cellular base stations using a marginal distribution technique

    Publication Year: 2001, Page(s):460 - 464 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (376 KB)

    A new statistical optimisation technique is presented and applied to the synthesis of a cellular base station antenna as an illustration of its potential. The algorithm is able to successfully specify an array that will meet the radiation pattern requirements in the GSM900 (880-960 MHz) and DCS1800 (1710-1880 MHz) bands of the GSM cellular telephone network. The basic design to be optimised is an ... View full abstract»

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  • Groundwave propagation predictions for the littoral environment (GRAPPLE)

    Publication Year: 2001, Page(s):792 - 796 vol.2
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (324 KB)

    A new engineering, propagation prediction tool, GRAPPLE, applicable between 10 kHz and 30 kHz has been described that offers significant benefits over the ITU recommended model, particularly for scenarios within the littoral environment. The ability to produce area coverage predictions with relative ease will aid the process of frequency management. As greater accuracy in the calculation of co-ord... View full abstract»

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  • Tunable radar absorbers using frequency selective surfaces

    Publication Year: 2001, Page(s):593 - 597 vol.2
    Cited by:  Patents (16)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (224 KB)

    Current techniques for controlling the radar cross-section (RCS) of military assets include careful shaping and the use of appropriate materials and construction methods. In general, these techniques are passive in the sense that once utilised in a particular asset, the latter cannot easily be modified to take account of new threat scenarios or operational requirements. Moreover, Rozanov (see IEEE... View full abstract»

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  • Modelling the installed performance of automotive antennas integrated with vehicle glazing

    Publication Year: 2001, Page(s):732 - 735 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (372 KB)

    The number of antennas deployed on modern vehicles is now rising very rapidly. In addition, styling and security considerations make conformal antennas particularly attractive for vehicle applications, despite the likelihood that the electromagnetic performance may be compromised. Thus, there is increasing interest in predicting the installed performance of automotive antennas. This paper outlines... View full abstract»

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  • Broadband probe-fed patch antenna with reduced cross-polarisation radiation

    Publication Year: 2001, Page(s):525 - 528 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (432 KB)

    This article presents novel designs of broadband patch antennas with reduced cross-polarisation radiation. The design for a 1×2 probe-fed E-patch subarray antenna fed by using two feeds of a 180°-phase shift is first demonstrated. Results for the same technique applied to a broadband single-patch microstrip antenna fed by dual L-strip coupled feeds are also presented. Finally, a new desi... View full abstract»

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  • In-situ optimization of cost function for genetic algorithm using neural networks applied to antenna design

    Publication Year: 2001, Page(s):456 - 459 vol.2
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (332 KB)

    In this paper, a neural network is used to implement a generalized cost function for a genetic algorithm (GA). Traditional GAs are inefficient because a large amount of data which describes the problem space is discarded after each generation. Using the neural network enhanced genetic algorithm (NNEGA), this redundant information is fed back into the GAs' cost function via the neural network. The ... View full abstract»

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  • Degradation in neural network prediction models of f0F2 with time

    Publication Year: 2001, Page(s):787 - 791 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (268 KB)

    Ionospheric forecasting services fall short of the precision required for many practical applications. In-service models of ionospheric parameters often fail to offer much of an increase in performance over simple persistence or recurrence. In particular, predictions of storm events and disturbances are very poor. This performance shortfall can be attributed to several causes one of which is an in... View full abstract»

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  • Scattering prediction of large finite sized phased array antennas using FDTD

    Publication Year: 2001, Page(s):715 - 718 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (244 KB)

    A method for the scattering prediction of large but finite sized phased array antennas is presented. The method employs the finite difference time domain (FDTD) method for infinitely periodic structures and a Fourier windowing technique. The method presented allows for more efficient analysis than simply modelling the entire array especially as the array size increases. The validity of the method ... View full abstract»

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  • Broadband analysis of finite microstrip patch antenna structure using FDTD

    Publication Year: 2001, Page(s):403 - 407 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (416 KB)

    Broadband analysis of a microstrip patch antenna on a finite substrate is investigated using the finite difference time domain (FDTD) method. The effects of varying the ground and dielectric size against the return loss at the input port and the far fields are discussed. Two different ways of feeding the antenna are addressed. The problem space size requirements of the FDTD method are presented. A... View full abstract»

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  • Wideband channel dynamics (measurement and simulation)

    Publication Year: 2001, Page(s):428 - 431 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (316 KB)

    The increasing demands on the limited frequency spectrum combined with the higher data rate requirements imposed by the convergence of data and voice services mean that increasingly, mobile operators are turning to spectrally efficient wideband systems such as code division multiple access (CDMA). However, in order to successfully implement capacity enhancement techniques, or to design a reliable ... View full abstract»

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  • Tunable single layer phase modulated radar absorber

    Publication Year: 2001, Page(s):588 - 592 vol.2
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (180 KB)

    Current military platforms utilise a combination of careful shaping and the use of appropriate materials and construction techniques to achieve low values of radar cross-section (RCS). Once built, however, they cannot easily be modified to take account of new threat scenarios or operational requirements. Hence, it might be desirable for future military platforms to be capable of some measure of dy... View full abstract»

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  • 2D Van Atta retrodirective array using dual polarized two-port square microstrip patches

    Publication Year: 2001, Page(s):814 - 816 vol.2
    Cited by:  Papers (12)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (164 KB)

    A retrodirective array possesses the advantage that the reradiation field from all the elements has a coherent phase in the arrival direction of the incident wave. Such an array is thus useful in applications such as collision avoidance systems, toll management, freight management etc. Well-known retrodirective antennas are the corner reflector, which is a 3D structure and the Van Atta (1959) arra... View full abstract»

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  • Simulation of microstrip small antennas

    Publication Year: 2001, Page(s):611 - 614 vol.2
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (480 KB)

    Microstrip patch antennas are being increasingly used in communication and radar systems because they have many advantages over conventional antennas, such as being lightweight, compact and conformal. There has been increased interest in minimising microstrip patch antennas for some specific applications, such as mobile communications and monolithic microwave integrated circuits. There are a numbe... View full abstract»

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  • First results of a long-term propagation experiment at 19 GHz

    Publication Year: 2001, Page(s):542 - 545 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (224 KB)

    A long term propagation experiment at 19 GHz and V polarisation on a 27.3 km long path was started in April 1995. The investigation was focused on attenuation due to hydrometeors (rain, hail, snow). The measured data from the 5-year period of observation were statistically processed and the cumulative time distributions of attenuation due to hydrometeors were obtained. The experiment was finished ... View full abstract»

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  • FDTD analysis of printed monopole antenna

    Publication Year: 2001, Page(s):728 - 731 vol.2
    Cited by:  Patents (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (296 KB)

    This paper presents FDTD analysis of a printed monopole antenna to give the guiding principle for the numerical simulation. As a result of the parameter study, the minimum number of cells is 10 for a distance between the absorbing boundary and the antenna for any ground plane size, whose guideline is very efficient to reduce the computing resource in FDTD calculations. When we used very fine grids... View full abstract»

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  • Spectral characteristics of propagation impairments on experimental Earth-space links at Ka and V bands

    Publication Year: 2001, Page(s):556 - 559 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (312 KB)

    Due to the increasing demand for multimedia services which require large bandwidth, and due to the saturation of low frequency bands such as L, S, C bands, as well as Ku band, satellite telecommunication systems are migrating to higher frequency bands such as Ka band (20/30 GHz) and V band (40/50 GHz). In such high frequency bands, the presence of the atmosphere strongly affects radiowave propagat... View full abstract»

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  • Delay profile in quasi-millimeter band for fixed wireless access in urban area

    Publication Year: 2001, Page(s):682 - 685 vol.2
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (268 KB)

    This paper describes the estimated delay profile in the quasi-millimeter band for a fixed wireless access system considering a statistical model of buildings in an urban area. The signal scattered by the buildings is estimated by the GTD method. Assuming random location of the buildings makes the estimation extremely complex: numerical integration corresponding to the Huygens-Fresnel principle is ... View full abstract»

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