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...

Dielectric waveguides are the structures that are used to confine and guide the light in the guided-wave devices and circuits of integrated optics. This chapter is devoted to the theory of these waveguides. Other chapters of this book discuss their fabrication by such techniques as sputtering, diffusion, ion implantation or epitaxial growth. A wellknown dielectric waveguide is, of course, the o...

Targeting the transition from a coaxial wave guide to a coplanar wave guide (CPW), a microwave and millimeter-wave wide-band coaxial-to-coplanar transition is proposed. This design connects the coaxial inner conductor to the CPW center conductor in a perpendicular manner to directly couple, on the same plane, the radial high-frequency electric field in the coax to the gap between the CPW’s cent...

Recently, millimeter wave applications are rapidly growing in modern high-speed and broadband wireless systems such as uncompressed HD-TV transmission, home link and radar for the collision prevention. In this paper, a NRD guide [1] fed dielectric lens antenna with high gain and low sidelobe characteristics is proposed for millimeter wave applications. The proposed antenna is designed on the ba...

An electromagnetic truncated Gaussian pulse propagates through a waveguide with piecewise diierent dielectric constants. The waveguide contains a barrier, namely a region of a lower dielectric constant compared to the neighboring regions. This setup yields a purely imaginary wave vector in the region of the barrier ('electromagnetic tunneling'). We exactly calculate the time-dependent Green's f...

For a good THz waveguide, both low propagating loss and small mode width are usually very important. However, the high ohmic loss of metals and the high absorption loss of dielectric materials result in that it still remains a challenge to obtain the two capabilities at the same time. In this paper, planar dielectric-gap-metal (DGM) waveguides are presented to guide THz wave. According to the d...

with the rapid growth of indoor wireless communication systems, the need to accurately model radio wave propagation inside the building environments has increased. many site-specific methods have been proposed for modeling indoor radio channels. among these methods, the ray tracing algorithm and the finite-difference time domain (fdtd) method are the most popular ones. the ray tracing approach ...

The scattering characteristic of paraxial gaussian beam from two dimensional dielectric rough surfaces is studied in this paper. The modification of the Kirchhoff approximation theory for rough surface scattering by an incident gaussian beam instead of a plane wave are developed based on conventional Kirchhoff scattering theory and plane wave spectrum expansion method. The coherent and incohere...

Ground penetrating radar (GPR) was used to characterize the frequency-dependent dielectric relaxation phenomena in ordinary Portland cement (OPC) hydration in concrete changing from fresh to hardened state. The study was experimented by measuring the changes of GPR A-scan waveforms over a period of 90 days, and processed the waveforms with short-time Fourier transform (STFT) in joint time-frequ...