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Antennas and Propagation, IEEE Transactions on

Issue 11 • Date Nov. 2008

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Displaying Results 1 - 25 of 35
  • Table of contents

    Publication Year: 2008 , Page(s): C1 - 3365
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    Freely Available from IEEE
  • IEEE Transactions on Antennas and Propagation publication information

    Publication Year: 2008 , Page(s): C2
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    Freely Available from IEEE
  • Investigations Into Phase Characteristics of a Single-Layer Reflectarray Employing Patch or Ring Elements of Variable Size

    Publication Year: 2008 , Page(s): 3366 - 3372
    Cited by:  Papers (35)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1040 KB) |  | HTML iconHTML  

    The paper reports on investigations into phase characteristic of a unit cell of a single-layer microstrip reflectarray, which includes patch or ring elements of variable size. The aim is to have a smaller gradient (slower slope) of the reflected wave phase as a function of the elements' size to achieve a wider operational bandwidth and smaller susceptibility to manufacturing errors. The results obtained for single resonance elements demonstrate that a slower slope can be achieved using thicker substrates at the expense of an inadequate phase range of less than 300deg. This inadequate phase range leads to the reflectarray elements phase errors, which reduce its directivity. To overcome this problem the use of multiresonance multiring elements is postulated. It is shown that square and circular shaped multiple rings printed on a thick substrate can offer a slower phase slope and the phase range exceeding 360deg. The achieved slopes and ranges of double rings are comparable with those of double stacked patches printed on the equivalent low permittivity dielectric substrate. Choosing suitable dimensions of double-ring elements, the phase characteristic can be made approximately a linear function of their size. View full abstract»

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  • 94 GHz Folded Fresnel Reflector Using C-Patch Elements

    Publication Year: 2008 , Page(s): 3373 - 3381
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1576 KB) |  | HTML iconHTML  

    A 94 GHz folded Fresnel reflector (FFR) for helicopter collision avoidance Radar is presented. The antenna system consists of a primary source illuminating a semi-reflecting grid that reflects the primary source polarization toward the main reflector opposite the grid. The main reflector has two functions. It focuses the field in the desired direction and rotates the incident polarization by 90deg to enable it to pass through the grid and radiate. Specific patch elements having a C-shape have been designed for this purpose. In order to increase overall efficiency, the reflector combines 8 correcting zones in its center and 4 at the periphery. The reflector is manufactured using standard photolithographic techniques. The primary source consists of a metal waveguide covered with a small frequency selective surface (FSS) for matching purposes. The maximum measured gain is 36.5 dBi at 94 GHz. The maximum side lobe level is -18 dB. The return loss value does not exceed -25 dB. The frequency bandwidth -3 dB in gain and return loss is 10%. In-flight measurements were conducted demonstrating the ability to detect power lines at distances up to 680 m. View full abstract»

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  • A Reconfigurable High-Gain Partially Reflecting Surface Antenna

    Publication Year: 2008 , Page(s): 3382 - 3390
    Cited by:  Papers (50)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (856 KB) |  | HTML iconHTML  

    A high-gain partially reflective surface (PRS) antenna with a reconfigurable operating frequency is presented. The operating frequency is electronically tuned by incorporating an array of phase agile reflection cells on a thin substrate above the ground plane of the resonator antenna, where the reflection phase of each cell is controlled by the bias voltage applied to a pair of varactor diodes. The new configuration enables continuous tuning of the antenna from 5.2 GHz to 5.95 GHz using commercially available varactor diodes, thus covering frequencies typically used for WLAN applications. Both the PRS and phase agile cell are analyzed, and theoretical and measured results for gain, tuning range, and radiation patterns of the reconfigurable antenna are described. The effect of the varactor diode series resistance on the performance of the antenna is also reported. View full abstract»

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  • Design of Shared Aperture Wideband Antennas Considering Band-Notch and Radiation Pattern Control

    Publication Year: 2008 , Page(s): 3391 - 3395
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (954 KB) |  | HTML iconHTML  

    Two wideband antennas sharing a common aperture are presented. One antenna consists of an electrically loaded rectangle monopole, an electrically loaded inverse L-shape monopole, and a lowpass matching network between the two monopoles. It covers 30-600 MHz (VSWR <3) with band-rejection characteristic in 86-110 MHz. The other one is a planar open-sleeve monopole, which covers 820-1200 MHz with VSWR<2. These two antennas are integrated in an aperture with size of only 420 times 200 mm2. Both antennas are planar, which are promising candidates for either vehicular or airborne applications. View full abstract»

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  • A Novel Circularly-Polarized Periodically-Loaded Mast Antenna for Vehicular Satellite Radio Reception

    Publication Year: 2008 , Page(s): 3396 - 3403
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1640 KB) |  | HTML iconHTML  

    A novel type of short monopole antenna is proposed. Its structure consists of a periodically slotted coaxial line radiating in linear polarization (LP). The structure can be easily modified by the addition of a thin layer of dipoles in order to generate circular polarization (CP). The number of slots along the structure, their periodicity and the tuning of the terminating load allow control of the antenna main beam' angle and width. One advantage of the proposed design over conventional monopoles is that the antenna does not require a ground plane. Both left-hand and right-hand CP are possible with the same design, simply by inverting the symmetry of the printed dipoles. Design details for the annular slotted coaxial line and for the LP and CP mast antennas are given. Prototypes in both LP and CP were fabricated and their characteristics were measured. Simulations and measurement are in good agreement. The proposed CP mast antenna is compliant with the requirements of the XM digital satellite radio system, with a frequency bandwidth of more than 1.7% in which <2, and an AR<4 in the elevation range of plusmn30deg< thetas < plusmn70deg . View full abstract»

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  • Dielectric Resonator Antenna on Silicon Substrate for System On-Chip Applications

    Publication Year: 2008 , Page(s): 3404 - 3410
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1160 KB) |  | HTML iconHTML  

    This paper presents for the first time the design and performance of a novel integrated dielectric resonator antenna fabricated on a high conducting silicon substrate for system on-chip applications. A differential launcher to excite the TE 01delta mode of the high permittivity cylindrical dielectric resonator was fabricated using the IBM SiGeHP5 process. The proposed antenna integrated on a silicon substrate of conductivity 7.41 S/m has an impedance bandwidth of 2725 MHz at 27.78 GHz, while the achieved gain and radiation efficiency are 1 dBi and 45% respectively. The design parameters were optimized employing Ansoft HFSS simulation software. Very good agreement has been observed between simulation and experimental results. The results demonstrate that integration of dielectric resonator antennas on silicon is viable, leading to the fabrication of high efficient RF circuits, ultra miniaturization of ICs and for the possible integration of active devices. View full abstract»

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  • Isolation Enhancement Between Two Closely Packed Antennas

    Publication Year: 2008 , Page(s): 3411 - 3419
    Cited by:  Papers (98)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (927 KB) |  | HTML iconHTML  

    This paper introduces a coupling element to enhance the isolation between two closely packed antennas operating at the same frequency band. The proposed structure consists of two antenna elements and a coupling element which is located in between the two antenna elements. The idea is to use field cancellation to enhance isolation by putting a coupling element which artificially creates an additional coupling path between the antenna elements. To validate the idea, a design for a USB dongle MIMO antenna for the 2.4 GHz WLAN band is presented. In this design, the antenna elements are etched on a compact low-cost FR4 PCB board with dimensions of 20times40times1.6 mm3. According to our measurement results, we can achieve more than 30 dB isolation between the antenna elements even though the two parallel individual planar inverted F antenna (PIFA) in the design share a solid ground plane with inter-antenna spacing (Center to Center) of less than 0.095 lambdao or edge to edge separations of just 3.6 mm (0.0294 lambdao). Both simulation and measurement results are used to confirm the antenna isolation and performance. The method can also be applied to different types of antennas such as non-planar antennas. Parametric studies and current distribution for the design are also included to show how to tune the structure and control the isolation. View full abstract»

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  • Wideband Circularly Polarized Vertical Patch Antenna

    Publication Year: 2008 , Page(s): 3420 - 3425
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (795 KB) |  | HTML iconHTML  

    A compact circularly polarized (CP) vertical patch antenna is presented that employs a microstrip to slot-line transition for a wideband operation. The antenna is composed of two vertical patches, which are shaped as helix to obtain a broadband CP performance. The loop structure and the vertical overlap configuration lead to significant size reduction as much as 48% when compared to that of the printed dual-loop antenna. Simulated results agree well with the measurement, showing that the antenna possesses a wide axial ratio (AR < 3 dB) bandwidth of 28.5%, and a broad return loss (S11 < - 10 dB) bandwidth of 37.8%. Also, it has symmetric radiation patterns and low cross-polarization levels in the broadside direction over the operating bandwidth. Moreover, the antenna gain is around 8 dBi, and it is very stable across the operating bandwidth. View full abstract»

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  • Integration of a Microstrip Circulator With Planar Yagi Antennas of Several Directors

    Publication Year: 2008 , Page(s): 3426 - 3432
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1061 KB) |  | HTML iconHTML  

    An integration methodology is presented to design antenna systems incorporating a ferrite circulator. Two integrated systems comprised of a microstrip circulator and Yagi planar-type antennas are presented as validation of the proposed methodology. Excellent pass band characteristics are observed in the experimental and numerical data for both systems. Furthermore, one system is magnetically tuned to realize 30 dB isolation over a bandwidth of 850 MHz. Both systems maintain excellent return loss and show improved insertion loss specifications even though the ferrite is biased into partial saturation. Extensive measurement data of the ferrite material and system network parameters are provided to corroborate the claims made herein. View full abstract»

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  • Dual-Polarized Microstrip Patch Planar Array Antennas With Improved Port-to-Port Isolation

    Publication Year: 2008 , Page(s): 3433 - 3439
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1326 KB) |  | HTML iconHTML  

    A method of preventing the degradation in the isolation between the orthogonal polarization ports caused by beamforming network routing in combined edge/aperture fed dual-polarized microstrip-patch planar array antennas is described. The simulated and measured performance of such planar arrays is demonstrated. Measured port isolations of 50 dB at center frequency, and more than 40 dB over a 4% bandwidth, are achieved. In addition, insight into the physical reasons for the improved port-to-port isolation levels, of the proposed element geometry and beamforming network layout, is obtained through prudent use of the electromagnetic modelling. View full abstract»

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  • Fast Analysis of Large Antenna Arrays Using the Characteristic Basis Function Method and the Adaptive Cross Approximation Algorithm

    Publication Year: 2008 , Page(s): 3440 - 3451
    Cited by:  Papers (60)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1698 KB) |  | HTML iconHTML  

    The characteristic basis function method (CBFM) has been hybridized with the adaptive cross approximation (ACA) algorithm to construct a reduced matrix equation in a time-efficient manner and to solve electrically large antenna array problems in-core, with a solve time orders of magnitude less than those in the conventional methods. Various numerical examples are presented that demonstrate that the proposed method has a very good accuracy, computational efficiency and reduced memory storage requirement. Specifically, we analyze large 1-D and 2-D arrays of electrically interconnected tapered slot antennas (TSAs). The entire computational domain is subdivided into many smaller subdomains, each of which supports a set of characteristic basis functions (CBFs). We also present a novel scheme for generating the CBFs that do not conform to the edge condition at the truncated edge of each subdomain, and provide a minor overlap between the CBFs in adjacent subdomains. As a result, the CBFs preserve the continuity of the surface current across the subdomain interfaces, thereby circumventing the need to use separate ldquoconnectionrdquo basis functions. View full abstract»

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  • Closed Form Modal Green's Functions for Accelerated Computation of Bodies of Revolution

    Publication Year: 2008 , Page(s): 3452 - 3461
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (683 KB) |  | HTML iconHTML  

    To solve problems of bodies of revolution (BoR) using the method of moments, the modal Green's function is used, which is defined as the radiation field of a circular loop antenna with sinusoidal current distribution. It is a group of oscillating integrals that forms the bottleneck for further accelerating the computation of BoR problems. In this paper, we propose closed-form expressions for near-axis far-distance modal Green's functions, which can be used to accelerate the computation of BoR problems especially when the object is slim. A criterion is presented based on a rigorous error analysis to guarantee its range of applications. Both the scattering and radiation examples are presented to demonstrate the validity and efficiency of the proposed expressions. View full abstract»

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  • Omega-Type Balanced Composite Negative Refractive Index Materials

    Publication Year: 2008 , Page(s): 3462 - 3469
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1265 KB) |  | HTML iconHTML  

    We report on the theoretical and experimental analysis of Omega-type metamaterials operating in X and Ku-bands. The prototypes are fabricated on the basis of metal waveguide technologies (hollow and TEM parallel plate) loaded with printed boards of interconnected Omega-shaped motifs. This interconnection of particles in the transverse direction leads to a broad left-handed band. Moreover, it is shown that such structures can be designed for a continuous negative-zero-positive index dispersion. This balanced composite behavior, so far known for periodically loaded transmission lines is verified experimentally with left- and right-handed dispersion branches extending from 8 to 12 and 12 to 16 GHz respectively. This zero-gap capability is explained on the basis of effective parameters retrieval. View full abstract»

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  • New Aspects of Electromagnetic Information Theory for Wireless and Antenna Systems

    Publication Year: 2008 , Page(s): 3470 - 3484
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (536 KB) |  | HTML iconHTML  

    This paper investigates information-theoretic characterization, via Shannon's information capacity and number of degrees of freedom, of wave radiation (antenna) and wireless propagation systems. Specifically, the paper derives, from the fundamental physical point of view of Maxwell's equations describing electromagnetic fields, the Shannon information capacity of space-time wireless channels formed by electromagnetic sources and receivers in a known background medium. The theory is developed first for the case of sources working at a fixed frequency (time-harmonic case) and is expanded later to the more general case of temporally bandlimited systems (time-domain fields). In the bandlimited case we consider separately the two cases of time-limited and essentially bandlimited systems and of purely bandlimited systems. The developments take into account the physical radiated power constraint in addition to a constraint in the source L 2 norm which acts to avoid antenna superdirectivity. Based on such radiated power and current L 2 norm constraints we derive the Shannon information capacity of canonical wireless and antenna systems in free space, for a given additive Gaussian noise level, as well as an associated number of degrees of freedom resulting from such capacity calculations. The derived results also illustrate, from a new information-theoretic point of view, the transition from near to far fields. View full abstract»

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  • Reduction of Truncation Errors in Planar Near-Field Aperture Antenna Measurements Using the Gerchberg-Papoulis Algorithm

    Publication Year: 2008 , Page(s): 3485 - 3493
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1041 KB) |  | HTML iconHTML  

    A simple and effective procedure for the reduction of truncation errors in planar near-field measurements of aperture antennas is presented. The procedure relies on the consideration that, due to the scan plane truncation, the calculated plane wave spectrum of the field radiated by the antenna is reliable only within a certain portion of the visible region. Accordingly, the truncation error is reduced by extrapolating the remaining portion of the visible region by the Gerchberg-Papoulis iterative algorithm, exploiting a condition of spatial concentration of the fields on the antenna aperture plane. The proposed procedure is simple and computationally efficient; it does not require any modification of the measurement procedure and it allows for the usual probe correction. Far-field patterns reconstructed from both simulated and measured truncated near-field data demonstrate its effectiveness and stability against measurement inaccuracies. View full abstract»

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  • A Method to Measure Radar Cross Section Parameters of Antennas

    Publication Year: 2008 , Page(s): 3494 - 3500
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (628 KB) |  | HTML iconHTML  

    A new method to measure radar cross section (RCS) parameters of antennas is presented in this paper. This method relies on an equation derived for the received signal power which is represented as the superposition of structural-mode scattered, antenna-mode scattered, and leakage signals. The method also measures relative phase and provides the effect of the load connected to the antenna. The received signal power equation is solved using minimum mean square error estimation, and the solution is used to obtain structural-mode RCS, antenna-mode RCS, and relative phase of an antenna by applying short, open, and match load cases. A measurement example of RCS parameters of a microstrip patch antenna using a simple experimental setup is presented. The structural-mode RCS, antenna-mode RCS, and relative phase factor cos(phi0) of the antenna, obtained using minimum mean square error estimation solution, are -18.307 dBsm, -20.386 dBsm, and 0.970, respectively. The present method requires less lengthy experimental measurements, while providing results that are more informative and accurate as obtained from previous methods. View full abstract»

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  • Finite-Element Time-Domain Analysis of Electrically and Magnetically Dispersive Periodic Structures

    Publication Year: 2008 , Page(s): 3501 - 3509
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1527 KB) |  | HTML iconHTML  

    A formulation is presented for the finite-element time-domain (FETD) analysis of periodic structures that contain electrically and/or magnetically dispersive materials. The formulation is based on the previously developed transformed field variable approach and the Floquet absorbing boundary condition, which are both applicable to arbitrary scan or incident angles. The paper describes an implicit finite-element time-marching equation for the transformed electric field variable coupled with a finite-difference type equation for the evaluation of the transformed magnetic field variable. The technique is applicable to general dispersive materials, although the required convolution calculations can be greatly accelerated when the electric and magnetic susceptibilities can be represented by a pole expansion. Numerical examples are presented to demonstrate the validity and capability of the proposed numerical approach which is effective for the efficient broadband analysis of complex periodic structures such as engineered materials and phased-array antennas. View full abstract»

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  • Observed Baseline Convergence Rates and Superconvergence in the Scattering Cross Section Obtained From Numerical Solutions of the MFIE

    Publication Year: 2008 , Page(s): 3510 - 3515
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (670 KB) |  | HTML iconHTML  

    The scattering cross section data obtained from numerical solutions of the magnetic field integral equation (MFIE), using a variety of basis functions and both Galerkin and non-Galerkin testing schemes, are compared to study the convergence rates of the results. For the basis functions considered, apparent superconvergence is observed in the MFIE scattering cross section when linear tangential/linear normal vector basis functions are used with Galerkin testing, but not with other basis functions. View full abstract»

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  • A Comprehensive New Methodology for Formulating FDTD Schemes With Controlled Order of Accuracy and Dispersion

    Publication Year: 2008 , Page(s): 3516 - 3525
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1087 KB) |  | HTML iconHTML  

    Numerical dispersion errors in the wave-equation-finite-difference-time-domain (WE-FDTD) method have been treated by higher order schemes, coefficient modification schemes, dispersion relation preserving and non-standard schemes. In this work, a unified methodology is formulated for the systematic generation of WE-FDTD schemes tailored to the spectrum of the excitation. The methodology enables the scheme designer to gradually trade order of accuracy (OoA) for lower dispersion errors in a controlled manner at the cost of sacrificing low frequency behavior, that is not deemed critical for this type of excitation. The methodology is shown to encompass both existing and new schemes. Stability analysis is carried out concurrently with the generation of each scheme. Using a stencil size of 3 and 5 temporal and spatial samples, respectively, long term errors of a scheme designed for a specific pulse are compared with the standard (4,4) scheme that has the same computational complexity, via simulation of a modulated pulse that propagates over a million time steps. View full abstract»

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  • Fast Analysis of RCS Over a Frequency Band Using Pre-Corrected FFT/AIM and Asymptotic Waveform Evaluation Technique

    Publication Year: 2008 , Page(s): 3526 - 3533
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (702 KB) |  | HTML iconHTML  

    The pre-corrected fast Fourier transform (PFFT)/adaptive integral method (AIM) is combined with the asymptotic waveform evaluation (AWE) technique to present fast RCS calculation for arbitrarily shaped three-dimensional PEC objects over a frequency band. The electric field integral equation (EFIE) is used to formulate the problem and the method of moments (MoM) is employed to solve the integral equation. By using the AWE method, the unknown equivalent current is expanded into a Taylor series around a frequency in the desired frequency band. Then, instead of solving the equivalent current at each frequency point, it is only necessary to solve for the coefficients of the Taylor series (called ldquomomentsrdquo) at each expansion point. Since the number of the expansion points is usually much smaller than that of the frequency points, the AWE can achieve fast frequency sweeping. To facilitate the analysis of large problems, in this paper, all the full matrices are stored in a sparse form and the PFFT/AIM method is employed to accelerate all the matrix-vector products on both sides of the matrix equation for the moments. Further, the incomplete LU preconditioner is used at each expansion point to improve the convergence behaviour of the matrix equation for the moments. The present method can deal with much larger problems than the conventional MoM-AWE method since the PFFT/AIM achieves considerable reduction in memory requirement and computation time. Numerical results will be presented to show the efficiency and capability of the method. View full abstract»

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  • An Efficient Ray Tracing Algorithm for Multiple Straight Wedge Diffraction

    Publication Year: 2008 , Page(s): 3534 - 3542
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (850 KB) |  | HTML iconHTML  

    We present an efficient algorithm for the tracing of multiply edge diffracted rays. The algorithm assumes a given sequence of infinite edges and complete visibility among them. The ray tracing problem is formulated as the minimization of the ray total path length. Since such a cost function is strictly convex, except for coplanar edges in the plane-wave far-field regime, then the problem admits a unique global minimum and allows the use of a modified Newton search algorithm, which exhibits a very high converging rate. We also propose a convenient starting point to effectively initialize the minimization algorithm. The proposed algorithm is tested by some numerical examples that show its efficiency and effectiveness. View full abstract»

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  • Extraction of Virtual Scattering Centers of Vehicles by Ray-Tracing Simulations

    Publication Year: 2008 , Page(s): 3543 - 3551
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1417 KB) |  | HTML iconHTML  

    Radar images of complex targets can be understood as a superposition of the reflected signals from a high number of scattering centers. To model complex targets for radar simulations, the plurality of scattering centers should be reduced to few significant scattering centers in order to minimize computational effort. The scope of this work is to present a technique to generate a significantly simplified RCS model of the vehicle with a limited number of virtual scattering centers, each with its own scattering characteristic, and how to group these scattering centers in a cluster database. The work is based on ray-tracing simulations of complex vehicle models. The ray-tracing simulations have been validated by measurements. The scattering centers may not be physically existing strong scattering centers, but virtual scattering centers representing a certain scattering behavior. In this paper, a technique for extracting such virtual scattering centers from a complex 3D-vehicle-model is presented. It is based on ray-tracing simulations of such models. As an example, the design model of a Ford Focus is used. View full abstract»

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  • Mean Effective Gain of Mobile Antennas in Line-of-Sight Street Microcells With Low Base Station Antennas

    Publication Year: 2008 , Page(s): 3552 - 3565
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1359 KB) |  | HTML iconHTML  

    A method for evaluating the mean effective gain (MEG) of mobile antennas in line-of-sight (LOS) street microcells with low base station antennas is investigated. The received power patterns of incident radio waves along typical streets measured in actual street microcells in urban areas of Tokyo are presented to clarify the proper distribution model for the incident radio waves. A two-dimensional statistical distribution model is proposed based on the measured received power patterns for the incident radio waves that follow a Gaussian distribution in the azimuth angle, but are concentrated in the horizontal plane in the elevation angle. The two-dimensional theoretical expression of the MEG that consists of the incident distribution model function and the radiation patterns in the horizontal plane of the mobile antennas is derived to evaluate easily the MEG. We show that the MEG values in street microcells are not defined as only one value and form the MEG pattern because the MEG values are changed by the relative direction of the radio waves arriving at the mobile station antennas. The measured and calculated MEG values (MEG patterns) of the whip antennas used in the experiments are in good agreement. The average error between the measured and calculated MEG values is within approximately 4.5 dB at maximum. The results show that the MEG degradation of the mobile station antennas due to the effect of the human body is properly evaluated by the proposed distribution model. The proposed statistical distribution model is valid and effective in both estimating the MEG values of mobile antennas and designing the LOS street microcell systems with low base station antennas. View full abstract»

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Aims & Scope

IEEE Transactions on Antennas and Propagation includes theoretical and experimental advances in antennas.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief                                                 Kwok W. Leung