110 research outputs found

    Synthetic TDR Measurements for TEM and GTEM Cell Characterization

    Get PDF
    This paper describes the main features of the timedomain reflectometry (TDR) measurement technique and, in particular, the TDR analysis performed using a proper operating mode of the vector network analyzer (VNA), which is called synthetic TDR. Furthermore, some results of reflection measurement, which aim to characterize the impedance behavior of transverse electromagnetic (TEM) and gigahertz TEM cells by means of a commercial VNA in time-domain mode, are presented

    Sharp Weyl Estimates for Tensor Products of Pseudodifferential Operators

    Get PDF
    We study the asymptotic behavior of the counting function of tensor products of operators, in the cases where the factors are either pseudodifferential operators on closed manifolds, or pseudodifferential operators of Shubin type on Rn\mathbb{R}^n, respectively. We obtain, in particular, the sharpness of the remainder term in the corresponding Weyl formulae, which we prove by means of the analysis of some explicit examples.Comment: 27 pages, 3 figures. Corrected typo

    On the Fredholm property of bisingular pseudodifferential operators

    Full text link
    For operators belonging either to a class of global bisingular pseudodifferential operators on Rm×RnR^m \times R^n or to a class of bisingular pseudodifferential operators on a product M×NM \times N of two closed smooth manifolds, we show the equivalence of their ellipticity (defined by the invertibility of certain associated homogeneous principal symbols) and their Fredholm mapping property in associated scales of Sobolev spaces. We also prove the spectral invariance of these operator classes and then extend these results to the even larger classes of Toeplitz type operators.Comment: 21 pages. Expanded sections 3 and 4. Corrected typos. Added reference

    Safety Checkpoints

    Get PDF
    partially_open9sìopenKazemipour, Alireza; Kleine-Ostmann, Thomas; Schrader, Thorsten; Allal, Djamel; Charles, Michael; Zilberti, Luca; Borsero, Michele; Bottauscio, Oriano; Chiampi, MarioKazemipour, Alireza; Kleine Ostmann, Thomas; Schrader, Thorsten; Allal, Djamel; Charles, Michael; Zilberti, Luca; Borsero, Michele; Bottauscio, Oriano; Chiampi, Mari

    Validation of numerical methods for electromagnetic dosimetry through near-field measurements

    Get PDF
    This paper describes the arrangement of a first experimental set-up which allows the comparison between the measurement of the electromagnetic field quantities induced inside a simple cylindrical phantom and the same quantities estimated numerically through a boundary element method. The reliability of the numerical method has been tested at 64 MHz, the Larmor frequency associated to the magnetic resonance imaging devices with an isocenter magnetic field of 1.5 T. To assess its robustness, the comparison is also performed by introducing, inside the phantom, a metallic non magnetic element, which roughly simulates a medical implant
    corecore