A recent analysis by Pendry #J. B. Pendry, Phys. Rev. Lett. 85, 3966 !2000"$ shows that a dielectric slab with a dielectric constant %!"1 can produce a perfect image in the electrostatic limit (c →&), independent of the permeability ', and therefore is a perfect lens. Here we include retardation effects and show how distance and dissipation make the lens no longer perfect. Nevertheless we concl...

Comparative studies of Cerium and Zirconium doped Barium Titanate S.N. Rahman, N. Khatun, S. Islam, N.A. Ahmed Industrial Physics Division, BCSIR Laboratories, Dhaka. Bangladesh Council of Scientific and Industrial Research (BCSIR) Dr. Kudrat-i-Khuda Road, Dhaka-1205, BANGLADESH. __________________________________________________________________________________________ Abstract: Comparative inv...

MnxNi0.5 _ xZn0.5Fe2O4, (x = 0.05, 0.1, 0.2, 0.3, 0.4) ferrites synthesized by the citrate precursor method are investigated in the present work. Compositional variation of AC resistivity is studied and values up to 10 times greater than those for samples prepared by the conventional ceramic method are observed. It is found that resistivity decreases with increase in Mn concentration except for...

We present mm-wave transmission as a complementary technique to characterize the properties of superconducting thin lms, obtaining information on both the real and imaginary part of the dielectric function. Examples are given to illustrate the strength of the technique to measure the response of dielectric materials and strati ed systems. We demonstrate the BCS-behavior of a conventional superc...

The high-frequency method for solving the scattering from homogeneous dielectric objects with electrically large size in half space is presented in this paper. In order to consider the scattering fields of the targets in half space, the half-space physical optics method is deduced by introducing the half-space Green’s function into the conventional physical optics method (PO). Combined with the...

Waveguide bends pose a problem for high-voltage uh.ra-wideband (UWB) systems or for any tr.ansmission-line system with low-loss/fast-risetime requirements, since only a straight section of conventional transmission line can support the pure TEM mode necessary to preserve the risetime of a transmitted pulse. Here we consider alternative concepts for compensation of waveguide bends. One concept, ...

We analyse the reflection of a TM electromagnetic field first on a flat dielectric film and second on a Veselago film with negative refractive index, both films being deposited on a metallic substrat acting as a mirror. An incident harmonic plane wave generates inside a conventional dielectric film a refracted propagating wave and an evanescent wave that does not contribute to reflection on the...

We present a numerical model for time domain reflectometry (TDR) signal propagation in dispersive dielectric materials. The numerical probe model is terminated with a parallel circuit, consisting of an ohmic resistor and an ideal capacitance. We derive analytical approximations for the capacitance, the inductance and the conductance of three-wire probes. We couple the time domain model with glo...

We report the realization of low-loss optical waveguiding at telecommunication wavelength by exploiting the hybridization of photonic modes guided by coupled all-dielectric nanowires and plasmon waves at planar metal-dielectric interfaces. The characteristics of the hybrid plasmon polaritons, which are yielded by the coupling between two types of guided modes, can be readily tuned through engin...

It is shown how the Debye rotational diffusion model of dielectric relaxation of polar molecules (which may be described in microscopic fashion as the diffusion limit of a discrete time random walk on the surface of the unit sphere) may be extended to yield the empirical Havriliak-Negami (HN) equation of anomalous dielectric relaxation from a microscopic model based on a kinetic equation just a...