archive-com.com » COM » T » TICRA.COM

Total: 410

Choose link from "Titles, links and description words view":

Or switch to "Titles and links view".
  • A High-Resolution Antenna Diagnostics Technique for Spherical Near-Field Antenna Measurements | TICRA
    spherical near field antenna measurements that is able to provide a high resolution of the reconstructed aperture field in excess of existing techniques is presented This is realized by using a transformation from the spherical wave expansion SWE determined from measurements to the plane wave expansion PWE recovering in this way also part of the invisible region of the plane wave spectrum By inverse Fourier transform OFT the aperture field

    Original URL path: http://www.ticra.com/papers/high-resolution-antenna-diagnostics-technique-spherical-near-field-antenna-measurements (2016-05-01)
    Open archived version from archive

  • Higher Order Hierarchical Legendre Basis Functions for Electromagnetic Modeling | TICRA
    Reflector antenna Scattering Higher Order Hierarchical Legendre Basis Functions for Electromagnetic Modeling Abstract This paper presents a new hierarchical basis of arbitrary order for integral equations solved with the method of moments MoM The basis is derived from orthogonal Legendre polynomials which are modified to impose continuity of vector quantities between neighboring elements while maintaining most of their desirable features Expressions are presented for wire surface and volume elements but emphasis is given to the surface elements In this case the new hierarchical basis leads to a near orthogonal expansion of the unknown surface current and implicitly an orthogonal expansion of the surface charge In addition all higher order terms in the expansion have two vanishing moments In contrast to existing formulations these properties allow the use of very high order basis functions without introducing ill conditioning of the resulting MoM matrix Numerical results confirm that the condition number of the MoM matrix obtained with this new basis is much lower than existing higher order interpolatory and hierarchical basis functions As a consequence of the excellent condition numbers we demonstrate that even very high order MoMsystems e g tenth order can be solved efficiently with an iterative solver in relatively

    Original URL path: http://www.ticra.com/papers/higher-order-hierarchical-legendre-basis-functions-electromagnetic-modeling (2016-05-01)
    Open archived version from archive

  • Electrical analysis of light-weight, triangular weave reflector antennas | TICRA
    requires accurate electromagnetic modelling of the reflector surface properties In particular the new tri axially woven fibre skins are of interest In a recent study for ESTEC a new computer program has been developed in a co operation between TICRA and Politecnico di Torino The name of the program is MESTIS MEtallic STrIps Simulator and by means of this it is possible to model one or more layers of strip

    Original URL path: http://www.ticra.com/papers/electrical-analysis-light-weight-triangular-weave-reflector-antennas (2016-05-01)
    Open archived version from archive

  • Creeping Wave Modes for a Dielectric Coated Cylinder | TICRA
    a Dielectric Coated Cylinder Abstract The spectrum of creeping waves that can exist on the sur face of a dielectric coated cylinder is determined by the poles in the Green s function for the cylinder Accounts of the position of these poles may be found in the literature but a number of poles appear so far to have been overlooked Although these poles may be of little interest for practical

    Original URL path: http://www.ticra.com/papers/creeping-wave-modes-dielectric-coated-cylinder (2016-05-01)
    Open archived version from archive

  • Reflector Antennas - An Overview of Surface Distortion Effects | TICRA
    Near field Optimization Physical Optics Reflectarray Reflector antenna Scattering Reflector Antennas An Overview of Surface Distortion Effects Abstract Reflector antenna surface distortions may be slowly varying rapidly varying systematic or random Typical examples of each of these types of surface distortions are presented and their consequences on the peak gain and side lobe performance are illustrated It is demonstrated that the impact on the radiation pattern is strongly dependent on

    Original URL path: http://www.ticra.com/papers/reflector-antennas-overview-surface-distortion-effects (2016-05-01)
    Open archived version from archive

  • Nonlinear Transformations for Accelerating the Convergence of M-Dimensional Series | TICRA
    Mode matching Multilevel Fast Multipole Method Near field Optimization Physical Optics Reflectarray Reflector antenna Scattering Nonlinear Transformations for Accelerating the Convergence of M Dimensional Series Abstract Two transformations for accelerating the convergence of infinite M dimensional series are presented They are generalizations of Shanks e transformation and Levin s one dimensional transformations respectively The transformations are compared with an M dimensional transformation by Levin in numerical examples Publication MATHEMATICS OF

    Original URL path: http://www.ticra.com/papers/nonlinear-transformations-accelerating-convergence-m-dimensional-series (2016-05-01)
    Open archived version from archive

  • Synthesis and analysis of single shaped reflector antennas | TICRA
    asymptotic theory describ ing electromagnetic fields of infinitely high frequencies only it has for several years constituted the foundation for synthesis of reflector antennas While dual reflectors are usually shaped to produce a certain aperture distribution leading to a pencil beam type pattern with high gain or low side lobes etc single reflectors may be synthesised to generate shaped beams by using the GO directly in the far field In

    Original URL path: http://www.ticra.com/papers/synthesis-and-analysis-single-shaped-reflector-antennas (2016-05-01)
    Open archived version from archive

  • Caustics and Caustic Corrections to the Field Diffracted by a Curved Edge | TICRA
    when the rays emanate from a source which is placed off the axis of the disk Either two or four singly diffracted rays appear dependent on the far field direction The caustics separate the region of space with two singly diffracted rays from the regions with four singly diffracted rays Corrections are derived which allow the ray description to be continued across the caustics These corrections depend on the local

    Original URL path: http://www.ticra.com/papers/caustics-and-caustic-corrections-field-diffracted-curved-edge (2016-05-01)
    Open archived version from archive



  •