Scheduled System Maintenance:
On May 6th, single article purchases and IEEE account management will be unavailable from 8:00 AM - 5:00 PM ET (12:00 - 21:00 UTC). We apologize for the inconvenience.
By Topic

Antennas and Propagation, IEEE Transactions on

Issue 6 • Date June 2006

Filter Results

Displaying Results 1 - 25 of 45
  • Table of contents

    Publication Year: 2006 , Page(s): c1 - 1617
    Save to Project icon | Request Permissions | PDF file iconPDF (46 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Antennas and Propagation publication information

    Publication Year: 2006 , Page(s): c2
    Save to Project icon | Request Permissions | PDF file iconPDF (41 KB)  
    Freely Available from IEEE
  • Compact multielement Marconi-Franklin type printed antennas for millimeter wireless systems

    Publication Year: 2006 , Page(s): 1618 - 1623
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1488 KB) |  | HTML iconHTML  

    Two novel Marconi-Franklin type printed antenna arrays, each consisting of three radiating elements arranged in a cascade configuration, are investigated. Both antennas are printed on a single high permittivity dielectric substrate and fed by SMA connectors, although coplanar waveguide (CPW) feed could easily be applied to further allow easier integration into an RF chip module. Two constructed prototypes, suitable for local-multipoint-distribution service operation in the 26-GHz band (25.5-26.5 GHz), are demonstrated. The constructed prototypes show an impedance bandwidth of about 1 GHz and a maximum gain of more than 5 dBi, with small variations (<1.8 dBi), is obtained across the achieved impedance bandwidth. Details of theoretical and experimental results showing impedance and radiation characteristics for both prototype antennas are given and discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Radiation of a coaxial line into a half-space

    Publication Year: 2006 , Page(s): 1624 - 1631
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB) |  | HTML iconHTML  

    We present a new approach to the problem of radiation by a coaxial line into a half-space. We obtain boundary-integral equations for the current densities over the walls of the coax and its opening to the half-space. Using the modes of the coax for basis and testing functions, we convert the integral equations to an infinite system of linear equations, the unknowns being the coefficients of the current density expansions. We demonstrate how, by solving a small subsystem, we can obtain the fields everywhere in space. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Metamaterial covers over a small aperture

    Publication Year: 2006 , Page(s): 1632 - 1643
    Cited by:  Papers (54)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1240 KB) |  | HTML iconHTML  

    Recently, there has been an increased interest in the problem of wave transmission through sub-wavelength apertures, following successful experimental demonstration by several groups for enhancing optical power transmission through nano-scale holes in metallic screens due to properly designed periodic corrugation. Oliner, Jackson, and their co-workers explained and justified this phenomenon as the result of the excitation of the leaky waves supported by the corrugated screen. Here we discuss in detail the mechanism and analysis for another setup we have recently proposed, in which metamaterial layers with special parameters may be utilized as covers over a single sub-wavelength aperture in a perfectly electric conducting (PEC) flat screen in order to increase the wave transmission through this aperture, and we provide a detailed physical insights and analytical explanation for this aperture setup that may lead to similar, potentially even more pronounced effects when the proper metamaterial layers are used in the entrance and the exit face of the hole in the flat PEC screen with no corrugation. Some numerical results confirming this theory are presented and discussed. We also investigate the sensitivity of the transmission enhancement to the geometrical and electromagnetic parameters of this structure. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electrically small antenna elements using negative permittivity resonators

    Publication Year: 2006 , Page(s): 1644 - 1653
    Cited by:  Papers (54)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (552 KB) |  | HTML iconHTML  

    We show how resonators composed of negative permittivity materials can form the basis of effective small antenna elements. A quasi-static analysis of the resonant properties of a sub-wavelength negative permittivity sphere predicts that such a resonator will have a Q-factor that is only 1.5 times the Chu limit, matching the performance of other known electrically small spherical antenna designs, such as the folded spherical helix and the spherical capped dipole. Finite element simulation is used to demonstrate an impedance-matched radiating structure formed by coupling the resonator (a half-sphere above a ground plane) to a 50 ohm coaxial transmission line, where the coupling is mediated by a small conducting stub extending partially into the half-sphere. The resulting antenna has a ka<0.5, and its bandwidth and efficiency performance corresponds well to that predicted by the quasi-static analysis of the resonator. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On artificial magnetodielectric loading for improving the impedance bandwidth properties of microstrip antennas

    Publication Year: 2006 , Page(s): 1654 - 1662
    Cited by:  Papers (45)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (768 KB) |  | HTML iconHTML  

    The effect of artificial magnetodielectric substrates on the impedance bandwidth properties of microstrip antennas is discussed. We review the results found in the literature and then focus on practically realizable artificial magnetic media operating in the microwave regime. Next, a realistic dispersive behavior of a practically realizable artificial substrate is embedded into the model. It is shown that frequency dispersion of the substrate plays a very important role in the impedance bandwidth characteristics of the loaded antenna. The impedance bandwidths of reduced size patch antennas loaded with dispersive magnetodielectric substrates and high-permittivity substrates are compared. It is shown that unlike substrates with dispersion-free permeability, practically realizable artificial substrates with dispersive magnetic permeability are not advantageous in antenna miniaturization. This conclusion is experimentally validated. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Conformal double exponentially tapered slot antenna (DETSA) on LCP for UWB applications

    Publication Year: 2006 , Page(s): 1663 - 1669
    Cited by:  Papers (30)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1976 KB)  

    We discuss the use of a double exponentially tapered slot antenna (DETSA) fabricated on flexible liquid crystal polymer (LCP) as a candidate for ultrawideband (UWB) communications systems. The features of the antenna and the effect of the antenna on a transmitted pulse are investigated. Return loss and E and H plane radiation pattern measurements are presented in several frequencies covering the whole ultra wide band. The return loss remains below -10 dB and the shape of the radiation pattern remains fairly constant in the whole UWB range (3.1 to 10.6 GHz). The main lobe characteristic of the radiation pattern remains stable even when the antenna is significantly conformed. The major effect of the conformation is an increase in the cross polarization component amplitude. The system: transmitter DETSA-channel receiver DETSA is measured in frequency domain and shows that the antenna adds very little distortion on a transmitted pulse. The distortion remains small even when both transmitter and receiver antennas are folded, although it increases slightly. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Study of printed elliptical/circular slot antennas for ultrawideband applications

    Publication Year: 2006 , Page(s): 1670 - 1675
    Cited by:  Papers (95)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (840 KB) |  | HTML iconHTML  

    Two novel designs of planar elliptical slot antennas are presented. Printed on a dielectric substrate and fed by either microstrip line or coplanar waveguide with U-shaped tuning stub, the elliptical/circular slots have been demonstrated to exhibit an ultrawideband characteristic. The performances and characteristics of the proposed antennas are investigated both numerically and experimentally. Based on these analyses, an empirical formula is introduced to approximately determine the lower edge of the -10 dB operating bandwidth. It is also shown that these antennas are nearly omnidirectional over a majority fraction of the bandwidth. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design of UWB folded-plate monopole antennas based on TLM

    Publication Year: 2006 , Page(s): 1676 - 1687
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1496 KB)  

    From the current distribution on planar monopoles, transmission line modeling is applied to study this kind of antennas. Some reported techniques for broadband monopoles are approached by using this model from a qualitatively point of view. Conclusions are derived that help to match the monopoles over an ultrawide bandwidth regardless of whether they are folded or not. Folded configurations are obtained in order to provide solutions to specific designs and improve radiation pattern maintaining the planar monopole broadband behavior. Three compact folded prototypes with greater than 1:38 bandwidth are implemented and tested. Pulse distortion is also discussed for this type of applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of the small band-rejected antenna with the parasitic strip for UWB

    Publication Year: 2006 , Page(s): 1688 - 1692
    Cited by:  Papers (86)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1056 KB) |  | HTML iconHTML  

    A novel band-rejected ultrawideband antenna with one parasitic strip is presented in this paper. It is designed to work on a substrate FR4 that has a thickness of 1 mm and relative permittivity of 4.6, and to operate from 3 to 17 GHz. The proposed antenna is fed by microstrip line and utilizes the parasitic strip to reject the frequency band (5.15-5.825 GHz) limited by IEEE 802.11a and HIPERLAN/2. The size of the antenna is 20×20 mm2 and this antenna has good radiation characteristics. Effects of varying the location and length of the parasitic strip and the structure of the ground and monopole patch on the antenna performance have also been studied. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Investigation into the performance of proximity coupled stacked patches

    Publication Year: 2006 , Page(s): 1693 - 1698
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (544 KB) |  | HTML iconHTML  

    We investigate the parameters that control the impedance and radiation performance of proximity coupled stacked microstrip patch radiators. In particular we explore the relationship required between the dielectric layers to achieve broadband behavior and also how the dimensions of the stacked radiators and the relative location of the feed can influence the impedance response. Bandwidths in excess of 20% can be achieved with careful layer design. We also investigate the dielectric layer configurations required to achieve broadband impedance responses when higher dielectric constant feed material is used. This latter study is of particular importance when designing MMIC compatible printed antennas. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Scan blindness phenomenon in conformal finite phased arrays of printed dipoles

    Publication Year: 2006 , Page(s): 1699 - 1708
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1272 KB) |  | HTML iconHTML  

    Scan blindness phenomenon for finite phased arrays of printed dipoles on material coated, electrically large circular cylinders is investigated. Effects on the scan blindness mechanism of several array and supporting structure parameters, including curvature effects, are observed and discussed. A full-wave solution, based on a hybrid method of moments/Green's function technique in the spatial domain, is used to achieve the aforementioned goals. Numerical results show that the curvature affects the surface waves and hence the mutual coupling between array elements. As a result, the array current distribution of arrays mounted on coated cylinders are considerably different compared to similar arrays on planar platforms. Therefore, finite phased arrays of printed dipoles on coated cylinders show different behavior in terms of scan blindness phenomenon compared to their planar counterparts. Furthermore, this phenomenon is completely different for axially and circumferentially oriented printed dipoles on coated cylinders suggesting that particular element types might be important for cylindrical arrays. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Technique for evaluation of profiles of a composite chiral slab through inversion and pseudospectral approximation

    Publication Year: 2006 , Page(s): 1709 - 1717
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (544 KB) |  | HTML iconHTML  

    In this paper, a technique is developed to simultaneously evaluate the permeability, permittivity and chirality parameter of a composite chiral slab where they are functions of depth of the slab. Additionally, the chirality parameter is a function of frequency. The developed technique is based on the use of the Riccati equation for the reflection coefficient associated with electromagnetic propagation through the slab and the Green functions. The technique also makes use of Nth degree interpolation polynomials to approximate the unknowns using Legendre-Gauss-Lobatto collocation nodes. A numerical example is given through which the application of the technique is utilized. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Indoor propagation models based on rigorous methods for site-specific multipath environments

    Publication Year: 2006 , Page(s): 1718 - 1725
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1048 KB) |  | HTML iconHTML  

    This paper presents a full wave simulation technique for modeling indoor propagation channels. A key feature of the technique is the use of a domain decomposition approach that accounts for repeatable components such as bricks, chairs, tables, etc. This leads to significant memory reduction, thus permitting the modeling of an entire classroom. Several simulations with different transmitting locations are presented and used to predict the statistical profiles of the received signal strength. These profiles are subsequently used to evaluate the bit error rate for specific digital modulation schemes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An attenuation time series model for propagation forecasting

    Publication Year: 2006 , Page(s): 1726 - 1733
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1240 KB) |  | HTML iconHTML  

    A key problem in the efficient use of higher (Ka- and V-band) frequencies lies in the mitigation of propagation impairments caused by meteorological phenomena. The traditional approach to this problem is based upon a relatively simplistic statistical model in the form of a fade margin. At higher frequencies this traditional approach becomes inefficient due to the large margin required. This inefficiency has lead to the introduction of dynamic fade mitigation techniques (FMTs). We present a method of generating attenuation time series that can be used for the development and evaluation of FMTs. The method we propose is based on the use of proven numerical weather prediction models in conjunction with a propagation model. This approach has two unique aspects. First, the spatial correlation and dynamic behavior of the attenuation fields are inherited from the meteorological environment. Second, the model can provide forecasts of attenuation. It is foreseen that this a priori knowledge of the occurrence of fades, their likely depth and likely duration can be exploited to manage the resource control of entire networks. This paper presents a description of the method and demonstrates the ability to generate attenuation time series. Conclusions are drawn regarding its use in real-time for network resource management. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • FDTD modeling of a novel ELF Radar for major oil deposits using a three-dimensional geodesic grid of the Earth-ionosphere waveguide

    Publication Year: 2006 , Page(s): 1734 - 1741
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1144 KB) |  | HTML iconHTML  

    This paper reports the first application of an optimized geodesic, three-dimensional (3-D) finite-difference time-domain (FDTD) grid to model impulsive, extremely low-frequency (ELF) electromagnetic wave propagation within the entire Earth-ionosphere cavity. This new model, which complements our previously reported efficient 3-D latitude-longitude grid, is comprised entirely of hexagonal cells except for a small, fixed number of pentagonal cells. Grid-cell areas and locations are optimized to yield a smoothly varying area difference between adjacent cells, thereby maximizing numerical convergence. Extending from 100 km below sea level to an altitude of 100 km, this technique can accommodate arbitrary horizontal as well as vertical geometrical and electrical inhomogeneities/anisotropies of the excitation, ionosphere, lithosphere, and oceans. We first verify the global model by comparing the FDTD-calculated daytime ELF propagation attenuation with data reported in the literature. Then as one example application of this grid, we illustrate a novel ELF radar for major oil deposits. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A spectral Integral method (SIM) for layered media

    Publication Year: 2006 , Page(s): 1742 - 1749
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1008 KB) |  | HTML iconHTML  

    A spectral integral method is presented for electromagnetic scattering from dielectric and perfectly electric conducting (PEC) objects with a closed boundary embedded in a layered medium. Two-dimensional layered medium Green's functions are computed adaptively by using Gaussian quadratures. The singular terms in the Green's functions and the non-smooth terms in their derivatives are handled appropriately to achieve exponential convergence. Numerical results, compared with the ones obtained by using other methods, demonstrate the spectral accuracy and high efficiency of the proposed method. They also confirm that the spectral integral method (SIM) is applicable to concave objects. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A UTD based asymptotic solution for the surface magnetic field on a source excited circular cylinder with an impedance boundary condition

    Publication Year: 2006 , Page(s): 1750 - 1757
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB) |  | HTML iconHTML  

    An asymptotic solution based on the uniform geometrical theory of diffraction (UTD) is proposed for the canonical problem of surface field excitation on a circular cylinder with an impedance boundary condition (IBC). The radius of the cylinder and the length of the geodesic path between source and field points, both of which are located on the surface of the cylinder, are assumed to be large compared to a wavelength. Unlike the UTD based solution pertaining to a perfect electrically conducting (PEC) circular cylinder, some higher order terms and derivatives of Fock type integrals are found to be significantly important and included in the proposed solution. The solution is of practical interest in the prediction of electromagnetic compatibility (EMC) and electromagnetic interference (EMI) between conformal slot antennas on a PEC cylindrical structure with a thin material coating on which boundary conditions can be approximated by an IBC. The cylindrical structure could locally model a portion of the fuselage of an aircraft or a spacecraft, or a missile. Validity and accuracy of the numerical results obtained by this solution are demonstrated in comparison with those of an exact eigenfunction solution. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Solution of the finite element vector Helmholtz equation by means of eigenvalue displacement

    Publication Year: 2006 , Page(s): 1758 - 1765
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB) |  | HTML iconHTML  

    In this paper, after an examination of the spectrum of the system matrix of the discrete vector Helmholtz equation, a novel technique that makes edge finite element matrices more suitable for Lanczos-based solvers is introduced. This technique works by displacing the eigenvalues related to static modes to a more favorable part of the spectrum. The displacement is achieved by means of a matrix that is added to the system matrix. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Additional boundary condition for the wire medium

    Publication Year: 2006 , Page(s): 1766 - 1780
    Cited by:  Papers (43)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1088 KB) |  | HTML iconHTML  

    In this paper, it is proved that the continuity of the tangential components of the average electric and magnetic fields is insufficient to describe the reflection of plane waves by a set of thin parallel wires embedded in a dielectric host using a homogenization approach. Based on physical arguments a new boundary condition is proposed to characterize the scattering of waves by the homogenized wire medium. In order to further support the proposed theory, the problem of reflection of a plane wave by a set of semi-infinite parallel wires is solved analytically within the thin-wire approximation. Extensive numerical simulations demonstrate that when the additional boundary condition is considered the agreement between full wave results and homogenization theory is very good even for wavelengths comparable with the lattice constant. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Applications of differential forms to boundary integral equations

    Publication Year: 2006 , Page(s): 1781 - 1796
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (544 KB) |  | HTML iconHTML  

    In this paper we discuss the application of differential forms to integral equations arising in the study of electromagnetic wave propagation. The usual Stratton-Chu integral equations are derived in terms of differential forms and corresponding Galerkin formulations are constructed. All numerical schemes require the specification of basis functions and the use of differential forms provides a very general method for the construction of arbitrary order basis functions on curvilinear geometries. It is noted that the lowest order approximations on flat geometries reduce to forms essential equivalent to the standard Rao-Wilton-Glisson functions. The effect on accuracy is investigated for electric field integral equation and magnetic field integral equation formulations for a range of bases. Hierarchical classes of functions are also developed, as are transition elements useful in p-adaptive schemes where variable orders of approximation are sought. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ray tracing with PO/PTD for RCS modeling of large complex objects

    Publication Year: 2006 , Page(s): 1797 - 1806
    Cited by:  Papers (39)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (864 KB) |  | HTML iconHTML  

    The present paper deals with a new efficient approach in order to assess the simulation of scattered fields from arbitrary metallic objects. The basic idea is to combine a ray tracing algorithm with the principles of physical optics (PO) and the physical theory of diffraction (PTD). The ray tracing algorithm stochastically launches discrete rays and uses a ray density normalization. In order to perform simulations at finite objects the PO/PTD formulation is required. Thus, fast intersection routines can be implemented, while the ray density formulation reduces the PO and PTD integrals to a pure sum of ray contributions. Simulation results obtained with this model are verified by comparison with both exact simulations using a method of moments (MoM) code and measurement results, proving an excellent accuracy and fast computation even at complex objects. With this asymptotic approach, scattering properties of large objects that are too complex for exact methods can be analyzed with rather moderate computation efforts. Typical applications include the simulation of low observability (LO) designs as well as the generation of databases for identifying unknown aircraft by their radar signature. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Scattering from small Salisbury screens

    Publication Year: 2006 , Page(s): 1807 - 1810
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (256 KB) |  | HTML iconHTML  

    This paper presents radar cross section results from a method of moments model of scattering from small Salisbury screens. Both normal and off-normal incidence is considered. The resistivity and separation of the resistive sheet and conductor are optimized for a square Salisbury screen having a side length between 0.5λ and 7.5λ. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Novel planar electromagnetic absorber designs using genetic algorithms

    Publication Year: 2006 , Page(s): 1811 - 1817
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (456 KB) |  | HTML iconHTML  

    A new type of absorber is proposed created by drilling holes in a single layer of lossy material. The new absorber is designed using genetic algorithms to achieve low reflectance over a wide frequency band. Results based on genetic algorithms demonstrate that the new absorber outperforms multilayer absorbers and absorbers embedding frequency selective surfaces between lossy materials. Numerical results are presented for different bandwidths, wave incidence angles, and polarizations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

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