T. Karpisz

Design of an applicator for microwave-assisted bituminous surface thermal bonding

In this paper a design cycle of an applicator for microwave-assisted bituminous surface thermal bonding is presented. The applicator is equipped with a waveguide nozzle and a hexagonal lattice of cylindrical metallic chokes preventing microwave leakage. The design is performed with the aid of electromagnetic simulations, based on a finite-difference time-domain method. Simulation results are initially validated with experiments and a good agreement is achieved.

Electromagnetic Modeling of Third-Order Nonlinearities in Photonic Crystal Fibers Using a Vector Two-Dimensional FDTD Algorithm

An algorithm accounting for dispersive and third-order nonlinear effects in a vector two-dimensional FDTD method is developed and validated in this paper. Kerr and Raman phenomena are implemented in FDTD using a new approach, which combines the accuracy of a rigorous FDTD update scheme and the speed of an approximate solution. As it is shown in this paper, the proposed method is applicable to the mode analysis of waveguide structures, like photonic crystal fibers, where the appropriate balance between dispersion and nonlinear phenomena is essential for supercontinuum generation. Several computational examples discussed in this paper successfully validate the proposed method.

Microwave Applicator for Thermal Treatment of Bituminous Surfaces

A comprehensive study of a microwave applicator for thermal treatment of bituminous surface is presented in this paper. The applicator consists of a customized rectangular waveguide horn surrounded with a hexagonal lattice of cylindrical chokes preventing hazardous leakage of microwave radiation beyond an exposure area. Electromagnetic simulations based on a finite-difference time-domain method are applied in a design process and afterward, the prototype is manufactured with the aid of computerized numerical control machining. Eventually, the applicator is applied for experimental testing of microwave-assisted thermal treatment of the trial bituminous surface, which demonstrates that microwave energy may be a viable alternative to typical thermal bonding techniques used in road construction and maintenance processes if appropriate conditions are met.

Open-ended waveguide measurement of liquids at millimeter wavelengths

In this paper, a measurement setup applicable to characterization of liquids at millimeter wavelengths is investigated. The system is composed of a vertically-oriented open-ended waveguide section, where the liquid under test can be easily poured. It is separated from waveguide measurement equipment with a dielectric window made of either fused silica of monocrystalline quartz. The advantage of the proposed approach is in the robustness of the design consisting of off-the-shelf components and a straightforward procedure for determining complex permittivity of high loss liquids with a decent accuracy.